The Ten Most Beautiful Experiments.Johnson2008

When Albert Einstein was an old man and sat down to write a short volume of autobiographical notes—“something like my own obituary”—he remembered the day his father showed him a compass. Turning it this way and that, the boy watched in wonder as the needle pointed insistently north. “I can still remember—or at least believe I can remember—that this experience made a deep and lasting impression upon me,” Einstein wrote. “Something deeply hidden had to be behind things.”

序幕

PROLOGUE

几年前一个晴朗的冬日清晨，我驱车上山，来到圣约翰学院，准备体验一番电子实验。我不久前刚认识了这所学校的校长。学校坐落在风景秀丽、与世隔绝的圣达菲山麓。令我印象深刻的是，学生们在人文课程的学习中，需要重现1909年罗伯特·密立根著名的电子实验。在那次实验中，密立根分离并测量了这些基本粒子，证明它们是由电场构成的。

ON A CLEAR winter morning several years ago, I drove up the hill to St. John’s College to play with electrons. I’d recently met the president of the school, which is nestled in the splendid isolation of the Santa Fe foothills, and was impressed to learn that the students, as part of their studies in the humanities, were expected to reenact the famous experiment of 1909 in which Robert Millikan isolated and measured these fundamental particles, showing them to be bits of electricity.

圣约翰学院和它在安纳波利斯的姊妹学院一样，秉承古典课程，物理学课程可追溯到公元前600年左右的前苏格拉底哲学家时期。当时，米利都的泰勒斯首次尝试提出大统一理论：“万物皆由水构成。” 如果放在今天，他或许会研究超弦理论。

St. John’s, like its sister college in Annapolis, pursues a classical curriculum, with physics starting around 600 BC with the Presocratic philosophers. That was when Thales of Miletus made the first stab at a Grand Unified Theory: “Everything is made of water.” Today he would probably be working on superstrings.

泰勒斯还注意到，产于马格尼西亚省的一种名为磁铁矿的岩石会对金属产生一种无形的吸引力；摩擦一块琥珀（希腊人称之为“elektron”）会使其带上一种神秘的电荷：它会吸引稻草和谷壳碎片。两千多年后，伊丽莎白一世女王的御医威廉·吉尔伯特注意到，用丝绸摩擦玻璃会使玻璃“琥珀化”——带电（他是第一个使用这个术语的人），并且其他材料也可以用这种方法带电。吉尔伯特推测，摩擦会使某种水状物质升温，从而产生一种粘稠的、气态的带电“逸散物”。法国化学家查尔斯-弗朗索瓦·德·西斯特奈·杜费进一步发现，摩擦过的琥珀会排斥物体，而摩擦过的玻璃则会吸引物体。他得出结论，电必定有两种形式：“树脂状”和“玻璃状”。事物背后隐藏着某种深藏的东西。密立根找到了理解它的方法。

Thales had also noticed that a rock called magnetite, found in the province of Magnesia, exerted an invisible pull on metal and that rubbing a piece of amber, a substance the Greeks called elektron, gave it a mysterious charge: it attracted pieces of straw and chaff. More than two thousand years later William Gilbert, Queen Elizabeth I’s physician, noted that glass rubbed with silk became “amberized”—electrified (he was the first to use the term)—and that other materials could also be enlivened this way. Friction, Gilbert speculated, heated some kind of watery humor giving rise to a sticky, vaporous “effluvium” of charge. A French chemist, Charles-François de Cisternay Dufay, went on to discover that rubbed amber repelled objects that rubbed glass attracted. Electricity, he concluded, must come in two forms: “resinous” and “vitreous.” Something deeply hidden lay behind things. Millikan found a way to get a grip.

我在一栋两层楼的英国领地风格建筑的地下室找到了物理实验室。这栋建筑前面是一条长长的白色走廊，周围环绕着松树。当时没有课，窗帘都拉上了，灯光也调得很暗。在房间的另一边，实验室主任汉斯·冯·布里森正在一张木制实验台上组装电子元件。圣约翰学院的一个习俗是，学生和老师（他们被称为导师）之间要用敬语称呼——冯·布里森先生、约翰逊先生——这使得走廊里的谈话听起来有点像《纽约时报》的专栏文章。

I FOUND the physics lab in the basement of a two-story Territorial-style building fronted by a long white veranda and surrounded by pines. Class was not in session, and the shades had been pulled, the lights turned low. At the far side of the room, the laboratory director, Hans von Briesen, was assembling electronic components on a wooden laboratory table. One of the customs at St. John’s is that students and teachers (tutors, they are called) address one another with honorifics—Mr. von Briesen, Mr. Johnson—making hallway conversations sound a little like the New York Times.

冯·布里森先生解释说，密立根实验的思路是利用香水喷雾器将微小的油滴喷入两块金属板之间的空间，其中一块金属板表面涂有树脂，另一块则涂有玻璃。在空气摩擦下，一些油滴会像泰勒斯的琥珀一样带电。通过改变两块金属板之间的电压，就可以使油滴上下移动，或者只需稍加控制，就能使其悬浮在半空中。

The idea of Millikan’s experiment, Mr. von Briesen explained, was to use a perfume atomizer to spray minuscule droplets of oil into a space between two metal plates, one charged resinously and the other vitreously. Rubbed by the air, some of the drops, like Thales’s amber, would become electrified. By varying the voltage across the two plates, a droplet could be made to move up and down, or with just the right touch to hover suspended in midair.

通过测量液滴的质量和阻止其下落所需的电压，可以确定其电荷量。测量足够多的液滴，就能看出电荷是像液体一样以任意数量存在，还是像零钱一样只能以离散的量存在。如果是后者，那么最小的电荷量就是电的基本单位——电子的电荷。

From the mass of the droplet and the amount of voltage required to counteract its fall, you can determine its charge. Measure enough droplets and you can see whether charge, like a fluid, comes in any amount whatsoever or, like pocket change, only in discrete quantities. If the latter is true then the smallest amount would be the elementary unit of electricity—the charge of the electron.

装置准备就绪，房间也暗了下来，实验开始了。经过几次试运行后，冯·布里森先生邀请我观看。我透过放大目镜——一个小型望远镜——观察着实验舱，看到了那些液滴。它们从后方被照亮，闪耀着如同星座或星系般的光芒。密立根本人曾这样描述它们：“这滴液滴看起来就像一颗璀璨的星辰。”

When the setup was complete and the room darkened the experiment began. After several trial runs Mr. von Briesen invited me to take a look. Gazing into the chamber through a magnifying eyepiece—a little telescope—I saw the droplets. Illuminated from behind, they shone like a constellation or galaxy. Millikan himself had described them this way: “The appearance of this drop is that of a brilliant star.”

二十一世纪的科学已经工业化。报纸上经常报道的那些实验——基因组测序、证实顶夸克的存在、通过分析遥远恒星的摆动发现新行星——耗资数百万美元。它们产生数TB的数据，需要由超级计算机进行分析：这些计算工厂散发出大量的热量，以至于需要配备冷却塔，其消耗的能源相当于几个小镇的能源。而执行这些实验的研究团队，其规模已经发展到堪比公司的水平。

SCIENCE in the twenty-first century has become industrialized. The experiments so often celebrated in the newspapers—sequencing the genome, proving the existence of the top quark, discovering a new planet by analyzing the wobble of a distant star—cost millions of dollars. They generate terabytes of data to be analyzed by supercomputers: calculating factories spewing so much heat that they are equipped with cooling stacks that consume the energy of small towns. The experiments are carried out by research teams that have grown to the size of corporations.

但直到最近，最具有划时代意义的科学发现都出自个人之手，出自某个人直面未知的探索。那些标志着我们认知边界的伟大实验，通常由一两位科学家在桌面上完成。即便有计算，也是在纸上进行，或者后来用计算尺完成。

But until very recently the most earthshaking science came from individual pairs of hands. From a single mind confronting the unknown. The great experiments that mark the edges of our understanding were most often performed by one or two scientists and usually on a tabletop. Computation, if there was any, was carried out on paper or later with a slide rule.

这些实验的设计和实施如此简洁优雅，堪称绝妙。这是古典意义上的美——装置的逻辑简洁，如同分析的逻辑简洁，如同希腊雕像的线条般纯粹而自然。困惑和歧义瞬间消散，自然界的全新面貌跃然眼前。

These experiments were designed and conducted with such straightforward elegance that they deserve to be called beautiful. This is beauty in the classical sense—the logical simplicity of the apparatus, like the logical simplicity of the analysis, seems as pure and inevitable as the lines of a Greek statue. Confusion and ambiguity are momentarily swept aside and something new about nature leaps into view.

作为一名科学作家，我常常被量子力学或广义相对论这类看似高深莫测的理论体系所吸引，它们试图用几条精妙的定律来概括现实。要了解这种探索已经变得多么抽象，只需看看超弦理论就知道了。超弦理论认为，物质最终是由在十维空间中振动的数学片段产生的。这固然引人入胜，但却如此深奥晦涩——远远超出了我的理解范围，或许也超出了任何人的理解范围——以至于我开始感到需要一些基础知识。

As a science writer, I have most often been attracted to airy edifices like quantum mechanics or general relativity, which seek to capture reality with a few courtly laws. For a sign of just how abstract this quest has become, one need look no further than superstring theory, which posits that matter is ultimately generated by mathematical snippets vibrating in ten-dimensional space. This is fascinating stuff, but so rarefied and confusing—so far over my, or maybe anyone’s, head—that I began to feel a need for basics.

《物理世界》杂志曾做过一项调查，询问读者他们认为最美的实验是什么。根据调查结果，杂志列出了十大实验，不出所料，全部都属于物理学领域。但我不禁思考，如果把范围扩大一些，结果又会如何呢？于是，我决定列出自己的榜单。

The magazine Physics World once conducted a survey asking its readers what they considered the most beautiful of all experiments. From the results, a roster was compiled of the top ten, all predictably within the realm of physics. But what, I wondered, if one were to cast the net wider? I decided to make my own list.

问题在于从何入手。从泰勒斯摩擦琥珀产生静电开始？这缺乏我所追求的那种优雅。没有对照组，也没有系统地尝试去探究哪些材料在什么条件下可以以这种方式带电。正如吉尔伯特后来指出的，琥珀并没有什么独特之处。在泰勒斯时代，实验科学尚未真正开始。

The question was where to begin. With Thales rubbing amber to create static electricity? That lacked the kind of elegance I was looking for. There were no controls, no systematic attempt to see what materials, under what conditions, could be charged this way. As Gilbert went on to show, there was nothing unique about amber. With Thales experimental science had not yet begun.

毕达哥拉斯，另一位前苏格拉底哲学家，他发现拨动琴弦发出的音符与精确的数学比例相对应。如果整根琴弦发出纯C音，那么四分之三的琴弦会发出F音，三分之二的琴弦会发出G音。将琴弦对折，它又会发出C音，只是音调高了一个八度。毕达哥拉斯宣称，万物皆数——这又是另一个大统一理论。他本该见好就收。他继续推测，火由24个直角三角形组成，周围环绕着4个等边三角形，而这4个等边三角形又由6个三角形组成。空气由48个三角形组成，水由120个三角形组成。实验让位于神秘主义。

How about Pythagoras, another of the Presocratics, who discovered that the musical notes sounded by a plucked string correspond to precise mathematical ratios? If the whole string sounds a perfect C, three-fourths of the string will sound an F and two-thirds a G. Pinch the string in half and it will sound a C again, an octave higher. All is number, Pythagoras declared—another Grand Unified Theory. He should have stopped while he was ahead. Fire, he went on to speculate, is made of twenty-four right-angle triangles, surrounded by four equilaterals, which are made in turn of six triangles. Air is composed of forty-eight triangles, water of one hundred and twenty. Experiment gave way to mysticism.

另一位候选人可能是阿基米德。关于他从浴缸里跳出来，高喊“尤里卡！”，发现浮力定律的传说，虽然真假难辨，却也掩盖了他成就的伟大。他的著作《论浮体》被认为是数学推理的杰作，这不仅是因为它推导出了阿基米德原理（浸没在流体中的物体会受到一个大小等于其所排开流体重量的向上力）。他还从基本原理出发，推导出了抛物面这种锥形物体浸入水中会漂浮的原理。（冰山大致呈抛物面形状，其运动特性与阿基米德的描述基本一致。）

Another candidate might have been Archimedes. The dubious legend about his jumping from a bathtub shouting “Eureka,” having discovered the physical law of buoyancy, trivializes the grandeur of his accomplishment. His treatise On Floating Bodies is considered a masterpiece of mathematical reasoning, and not just because of its derivation of Archimedes’s principle (a body submerged in a fluid is acted upon by an upward force equal in magnitude to the weight of the fluid displaced). He also figured out, from first principles, how a cone-shaped object called a paraboloid would float if immersed in water. (Icebergs are roughly paraboloid and behave pretty much as Archimedes said.)

然而，他的伟大之处更多地在于推理而非实验。又一位伟大的理论家。我一直在寻找的是那些罕见的时刻：一位充满好奇心的人，利用手头现有的材料，找到一种方法向宇宙提出问题，并坚持不懈直到得到回应。理想情况下，实验装置本身应该是一件艺术品，采用抛光木材、黄铜和闪亮的黑色硬橡胶制成。更重要的是设计和执行的美感，以及思路的清晰流畅。

His greatness, however, lay more in reasoning than in experiment. Another great theorist. What I was looking for were those rare moments when, using the materials at hand, a curious soul figured out a way to pose a question to the universe and persisted until it replied. Ideally the apparatus itself would be a thing of beauty, with polished wood, brass, shining black ebonite. More important would be the beauty of the design and the execution, the cleanness of the lines of thought.

为此，我不得不从古希腊一路跳跃到十七世纪，那时一位名叫伽利略的人发现了运动的基本定律。从那里开始，我一步一步地走下去，探访了科学之路上的另外九个站点，最终再次与密立根和他的小恒星相遇。

For that I had to jump from ancient Greece all the way to the seventeenth century, when a man named Galileo coaxed out a fundamental law of motion. From there, I proceeded step by step, visiting nine more stops on the scientific trail, eventually meeting up again with Millikan and his tiny stars.

很可能，任何读过这本书的人都能列出一份不同的清单。“你为什么不直接叫它《十大精彩实验》呢？”一位朋友反驳道。或许确实如此。但我希望这种随意性中蕴含着艺术，无论是我选择这些实验，还是我选择讲述每个实验的内容。这本书并非讲述伟大的发现，也不是关于那些偶然的惊喜，比如伽利略观测到环绕木星的卫星，或是查尔斯·达尔文对雀类的观察。那些并非我想要探索的那种经过深思熟虑、精心控制的对现实的探究。这本书也并非旨在成为一部微型科学传记集——这类优秀的传记已经汗牛充栋。有些科学家的生平，比如安托万-洛朗·拉瓦锡和阿尔伯特·迈克尔逊，以其奇特的细节吸引着我。而另一些科学家的生平，比如伽利略和牛顿的，则已被讲述得太多。我试图用炭笔勾勒出每位科学家的形象。我希望实验本身，而不是实验者，成为主角。

Likelier than not, anyone who reads this book could come up with a different list. “Shouldn’t you just call it Ten Beautiful Experiments?” a friend objected. Probably so. But I hope that there is art in the arbitrariness, both in my selection of the experiments and in what I have chosen to tell about each one. This is not a book about great discoveries, the serendipitous surprises like Galileo’s spying of satellites circling Jupiter or Charles Darwin’s observations about finches. Those were not the kind of deliberate, controlled interrogations of reality that I wanted to explore. Nor is this intended as a collection of miniature scientific biographies—there are already plenty of good ones. Some lives, like those of Antoine-Laurent Lavoisier and Albert Michelson, diverted me with their strange details. Others, like Galileo’s and Newton’s, have been told too many times before. I’ve tried to sketch each scientist with a charcoal wash. I want the experiment, not the experimenter, to be the protagonist.

为了使故事尽可能简洁明了，我尽量避免赘述功劳归属，也避免卷入历史学家们的争论。詹姆斯·焦耳关于能量和热的惊人发现，罗伯特·迈耶早有预料，但焦耳才是真正完成这项精妙实验的人。我很喜欢开尔文勋爵对此的评价：“个人优先性的问题，无论对当事人而言多么重要，与更深入地了解自然奥秘相比，都显得微不足道。”

To keep the stories as crisp as possible, I’ve spent little ink trying to parcel out credits, fighting the historians’ fights. James Joule’s surprising discovery about energy and heat was anticipated by Robert Mayer, but it was Joule who did the beautiful experiment. I like what Lord Kelvin had to say about that: “Questions of personal priority, however interesting they may be to the persons concerned, sink into insignificance in the prospect of any gain of deeper insight into the secrets of nature.”

第一章

CHAPTER 1

伽利略

Galileo

事物真正运转的方式

The Way Things Really Move

伽利略·伽利莱，作者：奥塔维奥·莱奥尼

Galileo Galilei, by Ottavio Leoni

看到一些自诩为某个研究领域内其他人的同行的人，想当然地认为某些结论是错误的，而这些结论后来却被其他人迅速而轻易地证明是错误的，这令人非常不快和恼火。

It is very unpleasant and annoying to see men, who claim to be peers of anyone in a certain field of study, take for granted certain conclusions which later are quickly and easily shown by another to be false.

——萨尔维亚蒂，《伽利略，两门新科学》

—Salviati, in Galileo, Two New Sciences

当你扔石头、接球或用力跳跃越过障碍时，大脑中较古老、无意识的部分——小脑——会毫不费力地展现出对基本运动定律的理解。力等于质量乘以加速度。每一个作用力都会产生一个大小相等、方向相反的反作用力。然而，这种根深蒂固的物理知识却与较新的、更高级的大脑——大脑皮层（智力和自我意识的中心）——隔绝开来。一个人可以像猫一样优雅地跳跃，却同样无力解释万有引力平方反比定律。

WHEN you throw a rock, catch a ball, or jump just hard enough to clear a hurdle, the older, unconscious part of the brain, the cerebellum, reveals an effortless grasp of the fundamental laws of motion. Force equals mass times acceleration. Every action results in an equal and opposite reaction. But this ingrained physics is sealed off from the newer, upper brain—the cerebrum, seat of intelligence and self-awareness. One can leap as gracefully as a cat but be just as powerless to explain the inverse square law of gravity.

公元前四世纪，亚里士多德首次尝试阐述运动规律，这是人类历史上首次雄心勃勃的尝试。物体下落的速度与其重量成正比——石头越重，落地越快。对于其他类型的运动（例如推动书本在桌面上移动或用犁耕地），必须持续施加力。你推得越用力，物体运动得越快。停止推动，物体就会停止。

Aristotle, in the fourth century BC, made the first ambitious attempt to articulate the rules of motion. An object falls in proportion to its weight—the heavier a rock, the sooner it will reach the ground. For other kinds of movement (pushing a book across a table or a plow across a field), a force must be constantly applied. The harder you push, the faster the object will go. Stop pushing and it will come to a halt.

这一切听起来都非常合情合理，显而易见，但实际上却大错特错。

It all sounds eminently sensible and obvious and, of course, is exactly wrong.

如果你把书放在冰面上，轻轻推一下，它会怎样？即使推力消失后，它仍然会继续运动。（有人问亚里士多德学派，为什么箭离开弓弦后还能继续飞行，他们说是被迎面而来的气流推动的。）现在我们知道，物体一旦开始运动，就会一直运动下去，直到被其他物体阻止，或者被摩擦磨损为止。一个一磅重的物体和一个五磅重的物体同时落下，它们会并排落地。伽利略证明了这一点。

What if you place the book on a sheet of ice and give it a gentle shove? It will keep moving long after the impetus is removed. (Asked why an arrow keeps going after it leaves the bowstring, the Aristotelians said that it was pushed along by the incoming rush of air.) Now we know that something set in motion stays in motion until stopped by something else, or worn down by friction. And a one-pound weight and a five-pound weight, dropped at the same moment, will fall side by side to the ground. Galileo showed it was so.

这位伟大的亚里士多德理论驳斥者——曾被贝托尔特·布莱希特搬上舞台，菲利普·格拉斯谱写歌剧，靛蓝女孩乐队也曾为他创作流行歌曲——最终遭到自己的理论驳斥，这完全在意料之中。历史学家告诉我们，伽利略从比萨斜塔上扔下两个重物的可能性微乎其微。他们也不相信他是在比萨大教堂里观察某个吊灯，并用心跳来计时，从而发现了关于钟摆的精髓——即每次摆动的时间都相等。

It’s entirely predictable that the great debunker of Aristotle—celebrated in a play by Bertolt Brecht, an opera by Philip Glass, and a pop song by the Indigo Girls—would come in for his own debunking. It is doubtful, historians tell us, that Galileo dropped two weights from the Leaning Tower of Pisa. Nor do they believe that he hit on his insight about pendulums—that each swing is of equal duration—while watching a certain chandelier in the cathedral of Pisa and timing it with his heartbeat.

在仔细审视下，伽利略作为宇宙学家的声誉也受到了质疑。伽利略是哥白尼日心说最雄辩的拥护者——他的《关于两大世界体系的对话》是第一部伟大的科普著作——但他始终没有接受开普勒的关键洞见：行星的运行轨道是椭圆形的。伽利略认为，行星的轨道必须是完美的圆形。在这一点上，他追随了亚里士多德的观点，亚里士多德宣称，虽然地球上的运动（在“月下”区域）必然有始有终，但天体的运动必然是圆形的。

His credentials as a cosmologist have also dimmed under scrutiny. Galileo was the most eloquent advocate of Copernicus’s sun-centered solar system—his Dialogue Concerning the Two Chief World Systems is the first great piece of popular science writing—but he never accepted Kepler’s crucial insight: that the planets move in ellipses. The orbits, Galileo assumed, had to be perfect circles. Here he was following Aristotle, who proclaimed that while motion on Earth (in the “sublunar” realm) must have a beginning and an end, celestial motion is necessarily circular.

要使之成立并与天空中的景象相符，行星的运动就不仅仅是绕圈，而是绕着圈做圈——正是这些老旧的本轮，拖累了托勒密的地心宇宙。伽利略对这个问题不以为意。最令人失望的是，他可能并没有像传说中那样，在被迫向罗马宗教裁判所道歉后，低声嘟囔一句“ Eppur si muove ”（然而它仍在运动）。他并非殉道者。他知道自己已经失败，于是隐居到阿尔切特里，独自舔舐伤口。

For that to be true and match what was happening in the sky, the planets would have to move not just in circles but in circles within circles—the same old epicycles that had weighed down Ptolemy’s geocentric universe. Galileo brushed off the problem. Most disappointing of all, he probably did not, as legend has it, follow his forced apology to the Inquisitors of Rome by muttering under his breath, Eppur si muove, “And yet it moves.” He was no martyr. Knowing he had been beaten, he retired to the solitude of Arcetri to lick his wounds.

伽利略最伟大的成就体现在他与梵蒂冈发生冲突之前所做的工作上。他研究的并非星辰或行星这样宏伟的天体，而是简单、平凡的物体的运动——这门学科远比任何人想象的都要复杂得多。

Galileo’s strongest claim to greatness lies in work he did long before his troubles with the Vatican. He was studying nothing so grand as stars or planets but the movement of simple, mundane objects—a subject far more perplexing than anyone had imagined.

这项研究是否真的始于比萨斜塔其实并不重要。他在另一部杰作《论两门新科学》中也描述过类似的实验，这部作品完成于他流亡生涯的最后几年。与早期作品一样，它也以三位意大利贵族——萨尔维亚蒂、萨格雷多和辛普利西奥——之间的长篇对话的形式展开，他们试图理解世界的运行规律。

Whether or not the research actually began at the Tower of Pisa hardly matters. He described a similar experiment in his other masterpiece, Discourses Concerning Two New Sciences, completed during his final years of exile. Like the earlier work it is cast as a long conversation among three Italian noblemen—Salviati, Sagredo, and Simplicio—who are trying to understand how the world works.

萨尔维亚蒂是伽利略的代表，在会议的第一天，他坚持认为，同时落下的100磅重的炮弹和1磅重的火枪弹几乎会同时落地。他承认，在一次实验中，较重的炮弹确实比较轻的炮弹提前了“两指宽”落地，但萨尔维亚蒂也意识到，空气阻力等其他因素会影响实验结果。关键在于，两颗炮弹的落地几乎是同时发生的：当炮弹落地时，火枪弹的飞行距离并非如常人所料的1/100——一肘。他斥责道：“你们不会用这两根手指来掩盖亚里士多德的99肘，也不会对我的小错误视而不见，而对他的大错误却保持沉默。”在其他条件相同的情况下，物体下落的速度与其重量无关。

Salviati is the stand-in for Galileo, and on the first day of the gathering he insists that, dropped simultaneously, a cannonball weighing 100 pounds and a musket ball weighing 1 pound will hit the ground at almost the same time. In an experiment, he concedes, the heavier one did in fact land “two finger-breadths” sooner, but Salviati recognized that other factors, like air resistance, muddied the results. The important point was that the impacts were almost in unison: when the cannonball hit the ground, the musket ball had not traveled just 1/100 the distance—a single cubit—as common sense would have predicted. “Now you would not hide behind these two fingers the ninety-nine cubits of Aristotle,” he chided, “nor would you mention my small error and at the same time pass over in silence his very large one.” All other things being equal, the speed at which an object falls is independent of its weight.

更难的问题是，球从被抛出到落地这段时间内发生了什么。球在运动过程中会逐渐加速——这是人人都知道的。但加速是如何发生的呢？是开始时有一个很大的加速，还是在整个下落过程中由许多小的加速持续进行的？

A harder question was what happened between the time a ball was released and the time it struck the ground. It would pick up speed along the way—everybody knew that. But how? Was there a large spurt of motion at the beginning, or a lot of little spurts continuing all the way down?

由于没有延时摄影或电子传感器来记录物体下落的时间，人们只能进行推测。伽利略需要的是一个类似的实验，一个下落速度更慢、更容易观察的实验：一个球沿着光滑平缓的平面滚动。适用于球的运动规律也应该适用于更陡的斜坡——以及最陡的斜坡：垂直向下。他找到了提出这个问题的方法。

With nothing like time-lapse photography or electronic sensors to clock a falling body, all you could do was speculate. What Galileo needed was an equivalent experiment, one in which the fall would be slower and easier to observe: a ball rolling down a smooth, gentle plane. What was true for its motion should be true for a steeper incline—and for the steepest: straight down. He had found a way to ask the question.

那一年大概是1604年。三十年后，他，或者更确切地说是萨尔维亚蒂，描述了这项实验的要点：

The year was probably 1604. Three decades later he, or rather Salviati, described the thrust of the experiment:

取一块长约十二肘、宽约半肘、厚约三指宽的木条或木料。在其边缘切出一条略宽于一指宽的凹槽。将这条凹槽打磨得笔直、光滑、抛光，并在其内衬上同样尽可能光滑抛光的羊皮纸后，我们沿着凹槽滚动一个坚硬、光滑且非常圆的青铜球。

A piece of wooden moulding or scantling, about 12 cubits long, half a cubit wide, and three finger-breadths thick, was taken. On its edge was cut a channel a little more than one finger in breadth. Having made this groove very straight, smooth, and polished, and having lined it with parchment, also as smooth and polished as possible, we rolled along it a hard, smooth, and very round bronze ball.

一块木料就是一块木头，佛罗伦萨肘尺是二十英寸，所以我们可以想象伽利略用一块二十英尺长、十英寸宽的木板，斜着把它支撑起来。

A scantling is a piece of wood, and a Florentine cubit was twenty inches, so we can imagine Galileo with a twenty-foot-long board, ten inches wide, propping it up at an angle.

我们将木板倾斜放置，一端比另一端高出一到两个肘尺，然后像我刚才说的那样，让球沿着凹槽滚动，并记录下球下降所需的时间（具体方法稍后会描述）。我们重复这个实验不止一次，以确保两次测量结果之间的偏差不超过脉搏的十分之一，从而精确测量时间。

Having placed this board in a sloping position, by lifting one end some one or two cubits above the other, we rolled the ball, as I was just saying, along the channel, noting, in a manner presently to be described, the time required to make the descent. We repeated this experiment more than once in order to measure the time with an accuracy such that the deviation between two observations never exceeded one-tenth of a pulse-beat.

十九世纪早期斜面实验的演示。滚动的球使铃铛发出声响。插图由艾莉森·肯特绘制。

An early-nineteenth-century demonstration of the inclined plane experiment. The rolling ball causes the bells to ring. Drawing by Alison Kent

萨尔维亚蒂接着解释说，他们完善了这项技术后，便开始计时，分别测量小球滑过四分之一、三分之二和四分之三轨道所需的时间。他们重复了实验，将轨道板设置在不同的坡度上——总共进行了100次测量。这些测量是用一种叫做水钟的简单装置进行的，它本质上是一个用液体而不是沙子来计量时间的沙漏：

Once they had perfected the technique, Salviati went on to explain, they timed how long it took the ball to traverse one-fourth of the track, then two-thirds, then three-fourths. They repeated the experiment with the board set at different slopes—100 measurements in all. These were taken with a simple device called a water clock, essentially an hourglass that parcels out seconds with liquid instead of sand:

我们使用了一台放置在高处的大型水箱。水箱底部焊接了一根细管，可以喷出细小的水流。每次下降过程中，无论下降的是整个通道的长度还是部分长度，我们都用一个小玻璃杯收集这些水流。每次下降后，我们都会用一台非常精确的天平称量收集到的水。通过比较两次称重的差值和比值，我们就能计算出每次下降的时间差值和比值。这种方法非常精确，即使重复多次，结果也几乎没有偏差。

We employed a large vessel of water placed in an elevated position. To the bottom of this vessel was soldered a pipe of small diameter giving a thin jet of water, which we collected in a small glass during the time of each descent, whether for the whole length of the channel or for a part of its length. The water thus collected was weighed, after each descent, on a very accurate balance. The differences and ratios of these weights gave us the differences and ratios of the times, and this with such accuracy that although the operation was repeated many, many times, there was no appreciable discrepancy in the results.

水的重量相当于时间的流逝。真是巧妙。但一些现代历史学家认为，这或许好得令人难以置信。大约三个世纪后，索邦大学的教授亚历山大·科伊雷读到伽利略的这段话时，几乎无法掩饰他的不屑：

The weight of the water was equivalent to the passage of time. Ingenious. But maybe, some modern historians have concluded, a little too good to be true. Reading Galileo’s words some three centuries later, Alexandre Koyré, a professor at the Sorbonne, could barely contain his scorn:

一个铜球在光滑的木槽里滚动！一个盛水的容器，上面有个小孔，水会从小孔流出，人们用小玻璃杯接住水，然后称重，以此来测量下降时间……这简直是误差和不精确性的集中体现！很明显，伽利略的实验完全没有价值。

A bronze ball rolling in a “smooth and polished” wooden groove! A vessel of water with a small hole through which it runs out and which one collects in a small glass in order to weigh it afterwards and thus measure the times of descent…What an accumulation of sources of error and inexactitude! It is obvious that the Galilean experiments are completely worthless.

科伊雷怀疑根本没有进行过实验——伽利略只是用滚动的球来做虚构的演示，作为一种教学手段，用来阐释他通过纯粹的演绎推理，用最传统的方式推导出的物理定律。看来，伽利略的理论又一次被驳斥了。

Koyré suspected that there had been no experiment—that Galileo was using an imaginary demonstration with rolling balls as a pedagogical device, an illustration of a law of physics that he had figured out mathematically, through pure deduction, the old-fashioned way. Galileo, it seemed, had been debunked again.

科伊雷是在 1953 年写下这些文字的。二十年后，伽利略科学研究领域的权威专家之一斯蒂尔曼·德雷克在佛罗伦萨国家中央图书馆的手稿中搜寻时，偶然发现了一些未发表的页面——伽利略自己的笔记本中的条目。

Koyré was writing in 1953. Twenty years later Stillman Drake, one of the leading experts on Galilean science, was sleuthing among the manuscripts in the Biblioteca Nazionale Centrale in Florence when he came across some unpublished pages—entries from Galileo’s own notebook.

伽利略有点囤积癖，当他的笔记在二十世纪初出版时，编辑安东尼奥·法瓦罗漏掉了一些页面，这些页面看起来只不过是一些潦草的涂鸦，一堆杂乱无章的计算和图表，让人摸不着头脑。这些页面显然顺序混乱，几乎无法判断它们的写作时间和作者当时的研究内容。

Galileo was something of a pack rat, and when his notebooks were published around the turn of the twentieth century, the editor, Antonio Favaro, had left out some pages that appeared to be no more than scribbles, a mess of calculations and diagrams that didn’t make sense. The pages were apparently out of order, with little clue as to when they had been written or what their author was working on.

德雷克当时正在研究《两门新科学》的新英文译本。 1972年初的三个月里，他待在佛罗伦萨，仔细研读伽利略论文集第七十二卷的160页，比对水印和笔迹，并尽可能地将这些页面恢复到合理的顺序。其中最早的几页似乎是1604年伽利略在帕多瓦时进行的实验数据。

Drake was researching a new English translation of Two New Sciences. For three months at the beginning of 1972, he sat in Florence going through 160 pages of the seventy-second volume of Galileo’s papers, comparing watermarks and styles of handwriting, restoring the pages to what seemed a sensible order. Among the earliest were what appeared to be data from the experiment of 1604, when Galileo was in Padua.

伽利略笔记本中的一页

A page from Galileo’s notebook

根据伽利略的笔记，德雷克重现了这个几个世纪前的实验，稍加改编，我们便能想象出伽利略当时的思路。他将小球放在木斜坡的顶端，并记录下最初几秒钟内，小球滑行了33个点（punti）。（伽利略使用的是一把刻度为60等分的尺子，德雷克推断，一个点略小于一毫米。）经过相同的时间后，小球速度加快，总共滑行了130个点，到第三个时间间隔结束时，滑行距离达到了298个点。然后是526、824、1192、1620……速度越来越快。这些都是真实的数据。至于小球达到最高速度时的最终距离，伽利略最初记录的是2123个点，后来划掉并更正为2104个点。在他的某些数据旁边，他标注了加号或减号，显然是为了表明他的测量结果偏高或偏低。

From the jottings, Drake re-created the centuries-old experiment, and with just a little license, we can imagine what was going through Galileo’s mind. He releases the ball at the top of the wooden incline noting that in the first few moments, it travels a distance of 33 punti, or points. (Galileo was using a ruler marked into sixty equal units, and a point, Drake deduced, was just shy of one millimeter.) After an equal amount of time has passed, the ball, picking up speed, covers a total of 130 punti, and by the end of the third interval, 298 punti. Then 526, 824, 1,192, 1,620…faster and faster. These were real data. For the final distance, when the ball would have been moving at top speed, Galileo had originally written 2,123 punti, scratching it out and correcting it to 2,104. By some of his figures, he put a plus or a minus sign, apparently indicating when his measurements seemed high or low.

他使用的时间单位并不重要。我们不妨称之为“滴答”。重要的是每个时间间隔都必须相同：

The units of time he was using don’t matter. We might as well call them ticks. The important thing is that each interval be the same:

滴答（时间）

ticks (time)

130

298

526

824

1,192

1,620

2,104

积分（累计距离）

punti (accumulated distance)

起初，并没有发现任何规律。每走一步，小球移动的距离就增加一分，但这究竟遵循什么规律呢？伽利略开始尝试不同的数字。也许速度的增加遵循某种算术级数。那么，交替使用奇数呢：1、5、9、13、17、21……？第二次走动时，小球的速度是第一次的五倍，移动距离为 5 × 33 = 165点。这个数值太高了，但或许还在实验误差范围内。第三次走动时，小球移动的距离是第一次的九倍：33 × 9 = 297点。这正好对！第四次走动时，13 × 33 = 429。这个数值太低了。然后是 17 × 33 = 561，这个数值太高了。而 21 × 33 = 693，这个数值又太低了……德雷克在手稿上看到了伽利略划掉这些数字，准备重新尝试的痕迹。

At first no pattern leaps forth. With each tick the ball covers more ground, but by what rule? Galileo started playing with the numbers. Maybe the speed increased according to some arithmetical progression. What about alternating odd numbers: 1, 5, 9, 13, 17, 21…? On the second tick the ball would move five times faster than on the first tick, covering 5 × 33 or 165 punti. Too high but maybe within the range of experimental error. The distance covered on tick three would be nine times greater: 33 × 9 = 297 punti. Right on the mark! And on the fourth tick 13 × 33 = 429. Too low. Then 17 × 33 = 561, too high. And 21 × 33 = 693, way too low…. Drake could see on the manuscript page where Galileo scratched out the numbers to try again.

第一次计时，球滑行了33个点，第二次是130个点。如果把这些数字相除呢？130/33=3.9。距离增加了将近四倍。第三次计时，距离增加了298/33，略多于初始距离的九倍。然后是15.9、25.0、36.1、49.1、63.8。他将这些数字四舍五入，然后用另一种墨水和笔将它们写成一列：4、9、16、25、36、49、64。

On the first tick the ball had covered 33 punti, then 130. What if you divide the numbers? 130/33 = 3.9. The distance had increased almost four times. With the third tick, the increase was 298/33, slightly more than nine times the initial distance. Then 15.9, 25.0, 36.1, 49.1, 63.8. He rounded the numbers and wrote them, using a different ink and pen, in a column: 4, 9, 16, 25, 36, 49, 64.

他找到了关键：允许存在一些误差，移动的距离与时间的平方成正比。使用更长的棋盘，人们可以自信地预测，下一次的倍数将是 81（ ^9²），然后是 100、121、144、169……伽利略的数字并不精确，这证明了实验的真实性。而它们如此接近精确值，则证明了他作为实验者的精湛技艺。

He had found the key: allowing for a bit of error, the distance covered increased with the square of the time. With a longer board, one could confidently predict that on the next tick the factor would be 81 (9²) and then 100, 121, 144, 169…. That Galileo’s numbers were not exact testified to the reality of the experiment. That they were as close as they were testified to his skill as an experimenter.

在这些计算中，距离是累加的：到第四个刻度时，小球的总运动距离是第一个刻度结束时的十六倍。但是，在第三个刻度到第四个刻度之间，小球分别运动了多远？与第二个刻度到第三个刻度之间相比，小球又运动了多远？答案可以通过算术反推得出。

In these calculations the distances are cumulative: by the fourth tick the ball has traversed a total of sixteen times the distance it covered at the end of the first tick. But how far does it travel during each separate interval, between ticks three and four compared with ticks two and three? The answer can be backed out with arithmetic.

平方数的本质在于，它们等于前面所有奇数之和：4 = 1 + 3；9 = 1 + 3 + 5；16 = 1 + 3 + 5 + 7。平方定律隐含着刻度线之间的距离必须随着奇数的增加而增大。伽利略的数据证明了这一点。

It is the nature of squares that they are the sums of the odd numbers that precede them: 4 = 1 + 3; 9 = 1 + 3 + 5; 16 = 1 + 3 + 5 + 7. Implicit in the times-square law is that the distances between ticks must increase according to the progression of odd numbers. Galileo’s data show how this works.

5…

滴答（时间）

ticks (time)

130

298

526

824…

积分（累计距离）

punti (accumulated distance)

130-33

97

298-130

168

526-298

228

824-526

298

punti（时间间隔内行进的距离）

punti (distance traveled in an interval)

97/33

2.9

168/33

5.1

228/33

6.9

298/33

9.0

距离比率

ratio of distances

一滴一滴地，小球滚动的距离依次是原来的三倍、五倍、七倍、九倍。事实上，伽利略本可以从奇数级数推导出平方关系。无论他采用何种方法，最终都得到了一条全新的基本定律：坡度越陡，小球滚动的速度越快，但始终遵循相同的规律——这条规律想必在坡度为90度（垂直向下）的情况下也成立。

Tick by tick the ball travels three times the distance, then five times, then seven, then nine. In fact Galileo could have started with the odd-number progression and derived the times-squared relationship. However he did it, the result was a fundamental new law. The steeper the slope, the faster the ball would roll, but always according to the same rule—which would presumably hold if the slope was ninety degrees, straight down.

在另一个极端情况下，如果斜率为零度，则不会产生加速度。小球沿斜面下滑后，一旦到达平坦的桌面，就会开始匀速运动——如果平面无限大且摩擦力忽略不计，这种匀速运动将永无止境。那么，如果运动的小球到达桌子边缘并掉落呢？在《两门新科学》的第四天，伽利略给出了答案：缓慢的水平运动和向下加速的垂直运动相结合，形成了我们熟悉的抛物线轨迹。

At the other extreme, a slope of zero degrees, there would be no acceleration. Once the ball, traveling down the incline, reached the flat tabletop, it would begin moving at a uniform speed—forever if the plane was infinite and friction didn’t interfere. And if the moving ball reached the edge of the table and dropped off? On the triumphant fourth day of Two New Sciences, Galileo provides the answer: the unhurried horizontal motion and the downwardly accelerated vertical motion combine to yield the familiar parabolic shape of a projectile.

伽利略是如何做到如此精确地计时，以不到一秒的时间间隔进行计时的，仍然是个谜。康奈尔大学的研究生托马斯·B·塞特尔用花盆代替水钟，让台球沿着一块2x6英寸的松木板滚动，在调整好反应速度后，他证明了乘法平方定律的有效性。但他和德雷克都怀疑，一个对计时一无所知的人，能否用如此简陋的装置发现其中的关系。德雷克认为，伽利略的方法更加精妙，也更加令人惊讶。

There was still the question of how Galileo did such precise timing, working with intervals of less than a second. Using a flowerpot as a water clock, a Cornell University graduate student, Thomas B. Settle, rolled billiard balls down a two-by-six pine plank and, once he had tuned his reflexes, demonstrated the validity of the times-squared law. But both he and Drake doubted that someone starting from ignorance could have discovered the relationship with so crude an apparatus. Galileo’s technique, Drake proposed, was more brilliant and surprising.

他意识到，伽利略其实没必要用现代的方式计时——用秒、半秒或其他任何传统单位。他只需要一种方法将时间均等分割，而德雷克认为，这对于任何优秀的音乐家来说都是一种与生俱来的天赋。

It wouldn’t have been necessary, he realized, for Galileo to clock time the modern way—in seconds, half seconds, or any other conventional measure. All that was needed was a way to divide time into equal portions, and this, Drake recognized, is a talent that comes naturally to any good musician.

德雷克写道：“乐团指挥挥动指挥棒，无需考虑秒或其他任何标准单位，就能在很长一段时间内精准地均匀分割时间。他根据内在节奏保持着某种均匀的节拍，并且能够反复地将节拍一分为二，其精确度堪比任何机械仪器。” 乐手甚至听众也是如此。“如果乐团中的钹手哪怕只差一瞬间，比如在乐谱中差了一个六十四分音符，所有人都会注意到，而不仅仅是指挥。”

“The conductor of an orchestra, moving his baton, divides time evenly with great precision over long periods without thinking of seconds or any other standard unit,” Drake wrote. “He maintains a certain even beat according to an internal rhythm, and he can divide that beat in half again and again with an accuracy rivaling that of any mechanical instrument.” The same goes for the musicians and even for the audience. “If the cymbalist in the orchestra were to miss his entry by a tiny fraction of a second, say by a 64th note in the music, everyone would notice it, not just the conductor.”

德雷克推测，伽利略的做法是这样的：在小球沿斜坡滚下之前，他先哼唱一首简单的曲子来确定节奏。德雷克用《前进，基督战士》这首歌做了个实验，节奏大约是每秒两拍。他把小球放在斜坡顶端，然后用粉笔在每个节拍的上半拍标记出小球的位置。

So, Drake speculates, this is what Galileo did: before the ball rolled down the incline, he established a rhythm by singing a simple tune. Drake tried the experiment with “Onward Christian Soldiers,” at about two beats per second. Releasing the ball at the top of the incline, he used chalk to mark its position at each upbeat.

前进吧，老基督徒们！

ONward CHRIStian SO-ol-DIER-rs MARCHing AS to…

就像德雷克一样，伽利略可能第一次也没能全部抓住它们，但在几次尝试之后，他会以大约半秒的间隔标记出轨迹，并颇为满意地注意到间距逐渐增大——球以合法的方式，越滚越快地滚下山坡。

Like Drake, Galileo probably hadn’t caught them all on the first run, but after several attempts he would have marked off the track in approximately half-second intervals, noting with some satisfaction that the spacing became progressively greater—that the ball, in a lawful manner, rolled faster and faster down the hill.

下一步是在每个粉笔标记处系上一段羊肠线，就像鲁特琴琴颈上的活动琴格一样——伽利略会弹奏这种乐器。德雷克用的是橡皮筋。他反复滚动小球，聆听它敲击琴格的声音，调整琴格的位置，直到咔哒声的节奏像节拍器一样均匀，与进行曲的节奏一致。完成后，琴格上的标记精确地显示了小球在等时间间隔内移动的距离。剩下的就是用尺子测量琴格之间的间距了。

The next step was to tie a piece of catgut at each chalk mark, like the movable frets on the neck of a lute, an instrument Galileo knew how to play. Drake used rubber bands. Rolling the ball again and again, he listened as it struck the frets, adjusting their placement until the rhythm of the clicking was as uniform as a metronome’s and in time with the march. When he was done, the frets showed precisely how far the ball had traveled during equal intervals of time. All that was left was to measure the spacing with a ruler.

德雷克认为，伽利略确立他的定律后，用一种更简便、但不太精确的方法向他人展示了它：事先在跑道上标记出数字——1、4、9、16、25、49、64——然后用水钟来验证时间。但这只是演示，而非实验。

Once Galileo had established his law, Drake believed, he showed it to others in an easier, less precise manner: by marking the track beforehand—1, 4, 9, 16, 25, 49, 64—and then using a water clock to confirm the timing. But that was a demonstration, not an experiment.

他为什么没有写下他最初的研究方法呢？德雷克能给出的最佳解释是，伽利略害怕显得愚蠢。“即使在他那个时代，写下‘我通过让小球沿平面滚动时唱歌来检验这条定律，结果证明它非常精确’也是很愚蠢的。” 不久之后，他就拿起望远镜，继续研究其他事物了。

Why didn’t he write about his original method? The best Drake could suggest is that Galileo was afraid of sounding silly. “Even in his day, it would have been foolish to write, ‘I tested this law by singing a song while a ball was rolling down a plane, and it proved quite exact.’” It wasn’t long before he had picked up his telescope and moved on to other things.

今天，在他逝世三百多年后，佛罗伦萨科学史博物馆的参观者可以看到他曾经用来捡起每次滑梯底部金属球并将其送回顶部的一根枯萎的手指。这根手指在他去世一个世纪后，他的遗体被掘出，迁葬到更好的墓地时，连同他的一颗牙齿、第五腰椎和另外几根手指一起被一位仰慕者取走。这根细长的手指被保存在一个圣物匣中，如同圣人的遗骨一般，手指向上指向天空，仿佛在召唤着天空。

Today, more than three hundred years after his death, visitors to the Museo di Storia della Scienza, the history of science museum in Florence, can see one of the withered fingers that picked up the metal ball each time it reached the bottom of the incline, returning it to the top for another ride. It was removed by an admirer, along with a tooth, the fifth lumbar vertebra, and a couple of other fingers, when Galileo’s body was exhumed, a century after his death, to be moved to a better burial site. Preserved in a reliquary like the bone of a saint, the long, thin finger has been mounted so that it points upward, as though beckoning to the sky.

伽利略的手指

Galileo’s finger

第二章

CHAPTER 2

威廉·哈维

William Harvey

心灵的奥秘

Mysteries of the Heart

威廉·哈维，威廉·范·贝梅尔绘

William Harvey, by Willem van Bemmel

但关于这流淌的鲜血的数量和来源，还有什么需要说明的呢？其性质如此新奇，闻所未闻，以至于我不仅担心会招致少数人的嫉妒，更害怕会与全人类为敌，因为许多习以为常的事情已经根深蒂固。教条一旦播下，便会扎根很深，对传统的敬畏影响着所有人。然而，木已成舟，我只能寄希望于我对真理的热爱和有教养之人的坦诚。

But what remains to be said upon the quantity and source of the blood which thus passes is of a character so novel and unheard-of that I not only fear injury to myself from the envy of a few, but I tremble lest I have mankind at large for my enemies, so much doth wont and custom become a second nature. Doctrine once sown strikes deep its root, and respect for antiquity influences all men. Still the die is cast, and my trust is in my love of truth and the candour of cultivated minds.

——威廉·哈维

—William Harvey

浸泡在温水中的鸡胚看起来像一小团云雾。它的蛋壳已被小心地剥去，里面跳动着一颗微小的心脏——一个比针尖还小的红点，随着每一次跳动忽隐忽现。多年后，在1628年，一位名叫威廉·哈维的伦敦医生描述了这种现象：“它仿佛介于可见与不可见、存在与不存在之间，通过它的脉动，象征着生命的开始。”

THE CHICK embryo lying in a container of tepid water looked like a little cloud. Its shell had been carefully peeled away, and inside there throbbed a minuscule heart—a red dot no bigger than a pinpoint that disappeared and reappeared with every beat. Years later, in 1628, a London physician named William Harvey described the phenomenon: “Betwixt the visible and invisible, betwixt being and not being, as it were, it gave by its pulses a kind of representation of the commencement of life.”

或许从来没有人研究过如此之多不同种类的心脏——狗的心脏、猪的心脏、青蛙的心脏、蟾蜍的心脏、蛇的心脏、鱼的心脏、蜗牛的心脏和螃蟹的心脏。有一种生活在海洋和泰晤士河中的虾，它的身体是透明的，哈维和他的朋友们会观察它的心脏跳动，“就像透过窗户看到的那样”。有时，他会把某种生物的心脏完全取出，感受它在他手中逐渐减弱的跳动，直到它停止最后的搏动。

Probably no one had ever studied so many different kinds of hearts—dog hearts, pig hearts, the hearts of frogs, toads, snakes, fishes, snails, and crabs. A certain kind of shrimp found in the ocean and in the river Thames had a transparent body, and Harvey and his friends would watch its heart gyrate “as though it had been seen through a window.” Sometimes he would remove a creature’s heart altogether, feeling the slowing rhythm as it beat its last beats in his hand.

哈维通过观察，逐渐说服自己——也几乎说服了所有人——伟大的盖伦，这位曾为角斗士和罗马皇帝行医的医生，是错的。盖伦在公元二世纪写道，人体有两种血液，分别由两种不同的血管系统输送。一种是滋养和生长的液体，由肝脏产生，流经遍布全身的蓝色血管网。与此同时，另一种鲜红色的生命液体则流经另一个血管网络——心脏和动脉——激活肌肉，促进运动。（在大脑中，部分生命液体转化为一种以太精华，流经神经。）所有这些体液都充满了无形的“灵气”，这种灵气随着每一次呼吸进入肺部，然后通过一条名为肺静脉的粗管流入心脏。一千四百年后，医学院的学生们仍然在学习这些内容。

Observation by observation, Harvey was persuading himself—and hardly anybody else—that the great Galen, physician to gladiators and Roman emperors, was wrong. Galen had written, in the second century AD, that there were two kinds of blood carried by what amounted to two different vascular systems. A vegetative fluid, the elixir of nourishment and growth, was made in the liver and coursed through the body’s web of bluish-colored veins. At the same time, a bright red vital fluid traveled through another network—the heart and arteries—activating the muscles and stimulating motion. (In the brain some of this vital fluid was turned into an ethereal essence that flowed through the nerves.) All the fluids were imbued with invisible pneuma, spirits that entered through the lungs with each breath before passing into the heart through a thick tube called the pulmonary vein. One thousand four hundred years later, this is what students were still being taught in medical school.

哈维的思想启蒙很可能始于剑桥。1593年，年仅十六岁的他进入了冈维尔与凯斯学院。这所学院的命名者约翰·凯斯博士是一位坚定的盖伦学派信徒，他曾安排获得一份皇家特许状，允许学院每年获得两名被处决的罪犯尸体进行解剖研究。除了修辞学、古典文学和哲学课程外，哈维也得以接触到人体解剖学。这门学科想必激起了他的兴趣。从剑桥毕业后，他进入了帕多瓦大学，这所大学是欧洲最负盛名的医学院。

Harvey’s indoctrination had probably begun at Cambridge, where in 1593 he entered Gonville and Caius College at the age of sixteen. The school’s namesake, Dr. John Caius, a committed Galenist, had arranged for a royal charter granting the school two executed criminals each year for dissection and study. Along with his lessons on rhetoric, classics, and philosophy, Harvey had glimpses of human anatomy. The subject must have piqued his interest. From Cambridge he went on to the University of Padua, the most prestigious medical school in Europe.

受威尼斯共和国的庇护，这所大学比大多数大学更敢于挑战梵蒂冈的教条。哈维抵达时，伽利略正在那里任教，欧洲最伟大的解剖学家耶罗尼米斯·法布里修斯也在那里任教。每年十月的圣路加节（天气凉爽，尸体保存时间更长），医学讲座以一场盛大的弥撒开始，之后学生们会聚集在解剖剧场的阶梯式阳台上，观看法布里修斯和他的助手们手持手术刀，带领学生们参观人体内部结构。

Protected by the republic of Venice, the university felt freer than most to challenge Vatican dogma. At the time of Harvey’s arrival, Galileo was teaching there, as was Hieronymus Fabricius, the greatest of Europe’s anatomists. Each October on Saint Luke’s Day (the corpses lasted longer in the cooler weather), the medical lectures began with a high mass, after which students would perch in the tiered balconies of the anatomy theater to watch as Fabricius and his assistants, scalpels in hand, gave a grand tour of the human interior.

1602年获得医学博士学位后，哈维返回伦敦，与皇家御医兰斯洛特·布朗的女儿结婚。他被任命到伦敦最古老的医院——圣巴塞洛缪医院任职，并在那里建立起自己的诊所，其病人包括弗朗西斯·培根爵士、詹姆斯一世国王以及詹姆斯一世的继任者查理一世。

After receiving his doctor’s degree in 1602, Harvey returned to London, where he married the daughter of Lancelot Browne, the royal physician. Appointed to a position at Saint Bartholomew’s, the city’s oldest hospital, he established a practice whose patients would include Sir Francis Bacon, King James I, and James’s successor, Charles I.

哈维身材矮小，相貌并不魁梧，但他那双深邃的黑眼睛和乌黑的头发，想必会给人留下深刻的印象。英国作家约翰·奥布里形容他既沉思又易怒（“他常说，人不过是一只顽劣的大狒狒”），而且习惯佩戴匕首。奥布里承认，这在当时是一种时尚。“但这位医生似乎动不动就拔出匕首。”

Though Harvey was short in stature and physically unimposing, his intense, dark eyes and raven hair must have made a formidable impression. The English writer John Aubrey described him as contemplative but choleric (“He was wont to say that man was but a great mischievous Baboon”) and in the habit of wearing a dagger. That was the fashion, Aubrey acknowledged. “But this Dr. would be to apt to draw-out his dagger upon every slight occasion.”

哈维的头脑就像一把手术刀。无论是在医院巡诊，还是在内科医师学会对着尸体讲课，人体解剖的任何细节都逃不过他的双眼。当发现某个器官与盖伦的理论不符时，哈维会委婉地指出，人体结构自盖伦时代以来发生了变化。但私下里，他却在拼凑出一个截然不同的故事。

Harvey’s mind was like a scalpel. Whether he was making his rounds at the hospital or lecturing over a cadaver at the College of Physicians, no detail of human anatomy was small enough to escape his eye. When an organ differed from what Galenic wisdom prescribed, Harvey would diplomatically suggest that bodies must have changed since Galen’s day. Privately he was piecing together a very different story.

他最初研究的是一些简单的生物，却沮丧地发现它们的心跳如此之快，以至于他几乎无法分辨其运动轨迹。他知道心跳有两种不同的方式：收缩期，即心脏收缩；舒张期，即心脏舒张。但当他在活体动物身上观察这一过程时，却发现根本无法区分这两种状态。

He started with simple creatures, finding to his dismay that their hearts fluttered so rapidly that he could barely make sense of the motions. He knew there were two different kinds of beats: the systole, when the heart contracted, and the diastole, when it expanded. But when he viewed the process in vivo, it seemed impossible to distinguish one from the other.

因为起初我既无法准确感知收缩期和舒张期何时发生，也无法分辨心脏扩张和收缩发生的时间和地点，这都是由于心脏运动极其迅速，在许多动物身上，这种运动只需眨眼之间即可完成，如同闪电般来去匆匆，以至于我一会儿觉得收缩期从这个点出现，一会儿又从那个点出现，舒张期也是如此。然后一切又颠倒过来，心脏运动似乎以各种混乱的方式同时发生。因此，我的心绪十分混乱，既不知道自己应该得出什么结论，也不知道该相信别人的说法。安德烈亚斯·劳伦提乌斯写道，心脏的运动就像欧里普斯的血流和回流令亚里士多德感到困惑一样，我对此并不感到惊讶。

For I could neither rightly perceive at first when the systole and when the diastole took place, nor when and where dilatation and contraction occurred, by reason of the rapidity of the motion, which in many animals is accomplished in the twinkling of an eye, coming and going like a flash of lightning, so that the systole presented itself to me now from this point, now from that, the diastole the same. And then everything was reversed, the motions occurring, as it seemed, variously and confusedly together. My mind was therefore greatly unsettled, nor did I know what I should myself conclude, nor what believe from others. I was not surprised that Andreas Laurentius should have written that the motion of the heart was as perplexing as the flux and reflux of Euripus had appeared to Aristotle.

劳伦提乌斯是文艺复兴时期的一位医生，欧里普斯海峡是希腊爱琴海沿岸的一条海峡，那里潮汐每天涨落七次。传说亚里士多德因无法理解潮汐的规律而沮丧，最终在那里投水自尽。

Laurentius was a Renaissance physician, and the Euripus was a strait along the Aegean coast of Greece where the tides move in and out seven times a day. Legend had it that Aristotle, dejected by his failure to understand these rhythms, drowned himself there.

如果哈维想要更好地研究心脏的脉动，他就需要像伽利略研究加速运动的球体那样，放慢速度观察这一现象。在“较冷的动物”——两栖动物、鱼类、爬行动物、甲壳类动物和软体动物——中，心脏跳动得更为缓慢。这些结构简单的心脏的运作原理可能与哺乳动物和人类的心脏相同。哈维通过一次又一次的实验，不断磨练自己的直觉，为将来更复杂的情况做好准备。因为他很快就会发现，在某些情况下，即使是温血动物的新陈代谢也会变得极其缓慢：在生命的最后几分钟，由于活体解剖而变得虚弱，可怜的动物的心跳越来越微弱，直到最终停止呼吸——或者说，停止呼吸，或者停止维持它生命的任何其他机制。

If Harvey was to do better with the tides of the heart, he would need to observe the phenomenon at a slower pace, as Galileo did with his accelerating balls. In the “colder animals”—the amphibians, fish, reptiles, crustaceans, and mollusks—the heart beat more leisurely. These simple hearts presumably worked according to the same principles as those of mammals and men. In one experiment after another Harvey tuned his intuitions for the more difficult cases to come. For there were circumstances, he was soon to learn, in which even the metabolism of a warm-blooded animal slows to a crawl: during the final minutes of life when, weakened by vivisection, the poor creature’s heartbeats become sparser and sparser until finally it gives up the ghost—or pneuma, or whatever had been keeping it alive.

尽管盖伦的两套循环系统在目的和功能上有所不同，但它们在心脏中彼此仅相距几毫米。由肝脏不断产生的淡蓝色血液，经由上腔静脉和下腔静脉流入和流出心脏的右侧心腔。在左侧，被一层称为隔膜的厚壁隔开，红色的动脉血在其中流动。血管也通向肺部，肺部负责冷却血液并将气（即“气”）输送到心脏。正是在心脏中，气为静脉血提供活力，其中极少量的静脉血通过隔膜上肉眼不可见的孔隙渗入动脉导管。

THOUGH different in purpose and function, the two circulatory systems of Galen came within millimeters of each other in the heart. Carried by the superior and inferior vena cava, the bluish blood—constantly generated by the liver—flowed into and out of the heart’s right-hand chambers. On the left side, sealed off by a thick wall called the septum, the red arterial blood flowed. Vessels also led to the lungs, which served to cool the blood and to carry pneuma—air—into the heart. It was there that the pneuma vitalized the venous blood, a tiny amount of which seeped across the septum through invisible pores and into the arterial ductwork.

这幅图景的部分内容早已受到质疑。佛兰德医生维萨里在其1543年首次出版的《论人体结构》（与哥白尼的日心说同年）中否认血液能够流过心脏的隔膜。他仔细观察，甚至找不到哪怕是最微小的孔隙。他的理由错了，但他的观点是正确的。我们现在知道，人体组织中布满了微小的孔隙。是哈维最终解决了这个问题：他小心翼翼地剖开一头牛的心脏，将水倒入右侧，发现水并没有流到左侧。

Some of this picture had already been called into question. The Flemish physician Vesalius, in Concerning the Fabric of the Human Body, first published in 1543 (the same year as Copernicus’s theory of heliocentrism), denied that blood could trickle across the heart’s dividing wall. As hard as he looked he couldn’t find even the tiniest pores. He was right for the wrong reason. We know now that bodily tissues are riddled with microscopic openings. It was Harvey who put the matter to rest: carefully cutting open an ox’s heart, he poured water into the right side and noted that none made its way to the left.

盖伦的追随者还认为，静脉血和动脉血这两种血液像潮汐一样在两个系统中往复流动。血管在生命能量的作用下，会同时扩张，吸入血液；当血管收缩时，血液则反向流动。心脏则像风箱一样，随着血液流动而扩张和收缩。

Galen’s followers also taught that the two kinds of blood—venous and arterial—moved like the tides, back and forth through the two systems. The vessels, animated by the vital spirit, expanded all at once, sucking up blood. When they contracted, the blood flowed the other way. The heart just went along for the ride, expanding and contracting like a bellows.

但哈维观察到的并非如此。心脏收缩时，也就是收缩期，就像一只手握成拳头一样，颜色变浅，仿佛血液被挤出来。心脏舒张时，也就是舒张期，颜色又变红，血液重新流入。更令人信服的是，当他用手指按压动脉时，他能感觉到动脉在心脏收缩的同时扩张。看来，心脏才是驱动血液循环的动力。盖伦的说法正好相反。推动血液流动的是心脏收缩的推力，而不是心脏舒张的拉力。在活体哺乳动物身上切开一条动脉，血液就会喷涌而出，“大量、猛烈，仿佛被注射器喷射而出”。

But that is not what Harvey was observing. When the heart contracted, on the systolic beat, like a hand bunching up into a fist, it became paler, as though blood was being squeezed out. When it expanded, on the diastole, it grew red again, as blood flowed back in. Even more telling, when he put his finger on an artery, he could feel it expand at the same time the heart contracted. The heart, it seemed, was driving the system. Galen had it backward. The push of contraction, not the pull of expansion, moved the blood. Cut an artery on a living mammal and blood came spurting out, “abundantly, impetuously, and as if it were propelled by a syringe.”

哈维推断，如果心脏是一个泵，他就应该能够了解它的工作原理。解剖学家们早已知道心脏分为四个腔室。上方是左右心房，下方是左右心室。一天，在一次解剖中，哈维将手指放在左心室上。左心室扩张，充满血液，与此同时，它上方的心房收缩。片刻之后，心室自身也收缩，将血液泵出腔室，进入动脉。同样的运动也发生在右心室。盖伦又错了。血液不是从右向左泵送，而是从上向下泵送：“这两个运动，一个来自心室，另一个来自心房，是依次发生的，”哈维写道，“但它们之间保持着某种和谐或节奏，两者协调一致，以至于我们只能看到一个运动。”

If the heart was a pump, Harvey reasoned, he should be able to learn how it worked. Anatomists already knew that it was divided into four chambers. On top were the left and right auricles, below them the left and right ventricles. One day during a dissection Harvey placed a finger on a left ventricle. It expanded, filling with blood, just as the auricle above it contracted. Then, an instant later, the ventricle itself contracted, pushing blood out of the chamber and into the arteries. The same motions occurred on the right side. Again Galen was wrong. Blood was pumped not from right to left but from top to bottom: “These two motions, one of the ventricles, the other of the auricles, take place consecutively,” Harvey wrote, “but in such a manner that there is a kind of harmony or rhythm preserved between them, the two concurring in such wise that but one motion is apparent.”

他将这种运动比作机器的运转：“一个轮子带动另一个轮子，但所有轮子似乎都在同时运动。”他知道有些读者可能会对这种机械式的描述感到冒犯，但这并非他的本意。“心脏除了推动血液流动、使其局部运动并将其输送到全身之外，是否还赋予血液其他功能——例如热量、精神、完美——这些都必须以后再探究，并根据其他依据来判断。”他怀疑人体远不止于生理过程，心脏是“微观世界的太阳”，血液是一种精神物质，“是上天的工具”。但这并不意味着我们不能系统地研究心脏的运动。

He compared the movement to a machine’s: “One wheel gives motion to another, yet all the wheels seem to move simultaneously.” He knew that some of his readers might be offended by this mechanical description. But that was not his intention. “Whether or not the heart, besides propelling the blood, giving it motion locally, and distributing it to the body, adds anything else to it—heat, spirit, perfection—must be inquired into by-and-by, and decided on other grounds.” He suspected that there was more to the body than physical processes, that the heart was “the sun of the microcosm” and blood a spiritual substance, “the instrument of heaven.” But that didn’t mean its motions could not be studied systematically.

格雷氏解剖学中的人类心脏横截面图

Cross section of a human heart from Gray’s Anatomy

这里引述的文字出自哈维的巨著《论动物心脏和血液的运动》。尽管略显重复，这本历经二十年研究后于1628年出版的小册子，至今仍值得一读。哈维如同检察官辩护一般，一步步地梳理证据。我们可以想象他站在法庭上，挥舞着仪式匕首，向陪审团陈述案情。

The words quoted here are from Harvey’s masterwork, On the Motion of the Heart and Blood in Animals. Though a bit repetitious, the short book, published in 1628 after two decades of research, still makes for a good read. With the tenacity of a prosecutor arguing a case, Harvey marshals his evidence one step at a time. We can imagine him in the courtroom, waving his ceremonial dagger and addressing a jury.

他首先请观众思考动脉系统。通过他的实验，现在可以清楚地看出，心脏左侧的作用是将血液泵入动脉，动脉再将血液输送到身体各处。同样显而易见的是，与潮汐不同，这是一种单向流动：左心室和主动脉之间有瓣膜，可以防止血液反流。

First he asks the audience to consider the arterial system. It was now clear from his experiments that the purpose of the left side of the heart was to pump blood into the arteries, which carried it toward the extremities of the body. It was also clear that unlike the tides this was a one-way flow: there were valves between the left ventricle and the aorta that prevented blood from sloshing back the other way.

接下来我们来看一下静脉系统。人们早就知道，腿部和手臂的静脉里有自己的瓣膜。哈维在帕多瓦的老师，伟大的解剖学家法布里修斯发现了这些静脉口，也就是“小门”，但他当时认为这些静脉口的作用仅仅是减缓血流速度，防止血液淤积。哈维通过将一根长探针插入血管，并向远离心脏的方向推进，发现了真相。探针遇到了阻力，但反方向推进时却很容易通过。静脉是单向通道。动脉血从心脏流向全身，静脉血则从全身流回心脏。

Consider next the venous system. It had long been known that veins in the legs and arms contained their own built-in valves. Harvey’s teacher in Padua, the great anatomist Fabricius, had discovered these ostiola, or “little doors,” but thought they served only to slow the blood and prevent gorging. Harvey found the truth by inserting a long probe into a vessel and pushing it in the direction leading away from the heart. The motion was resisted. But it slipped through easily when thrust the other way. The veins were one-way avenues. Arterial blood was pushed out from the heart to the body. Venous blood flowed from the body back to the heart.

最后，我们来考虑一下静脉血是如何从右心室（血液接收的地方）流向左心室的。哈维已经确定血液并非通过室间隔流动。这样就只剩下一条可能的路径——连接右心室和肺部的肺动脉。流经这条血管的不是空气，而是血液。血液以某种方式扩散穿过肺部的海绵状组织，最终经由肺静脉流出，进入心脏的左心耳。结论显而易见：心脏的右侧将血液泵入肺部，左侧将血液泵入全身。

Finally consider how the venous blood might get from the right chambers, where it was received, to the left. Harvey had already established that the flow was not through the septum. That left only one possible path—the pulmonary artery connecting the right ventricle to the lungs. It was not air that flowed down the vessel but blood that flowed up the other way. Diffusing somehow through the lungs’ spongy tissues, the fluid exited through the pulmonary vein, which led to the left auricle of the heart. The conclusion was inescapable: the right side of the heart pumped blood through the lungs, the left side pumped blood through the body.

哈维并非第一个想到这一点的人。上个世纪，西班牙神学家兼医生米歇尔·塞尔维特曾在一篇宗教文章中推测过肺循环：“正如上帝用空气使血液鲜红，基督也使圣灵发光。”（他的解剖学论证是对三位一体教义的攻击，最终他被新教徒处以火刑。）维萨里的助手雷亚尔杜斯·哥伦布也注意到，从肺部返回的液体呈鲜红色，这表明血液的活力是在肺部而非心脏中产生的。哈维提出了一个关键问题：如果心脏右半球将血液泵入肺部，再由左半球泵入动脉……那么，动脉血到达目的地后会发生什么？源源不断的静脉血又从何而来？

Harvey wasn’t the first to think of this. In the previous century, a Spanish theologian and physician, Michael Servetus, had speculated about the pulmonary circulation in a religious tract: “Just as by air God makes ruddy the blood, so does Christ cause the Spirit to glow.” (His anatomical arguments were part of an attack on the Trinity, and he was ultimately burned—by Protestants—at the stake.) Picking up on the theme, Realdus Columbus, an assistant to Vesalius, noted that the fluid returning from the lungs was bright red, suggesting that vitalization occurred there and not in the heart. It was left for Harvey to ask the crucial question: If the right side of the heart pumps blood through the lungs and into the heart’s left side, and if the left side then pumps it out into the arteries…then what happens to all the arterial blood when it reaches its destination, and where does the endless supply of venous blood come from?

盖伦学派给出了答案：血液和血都由食物摄入不断生成，并在身体生长和运动过程中消耗。哈维决定计算一下。他通过解剖发现，左心室能够容纳两盎司或更多的血液，但每次心跳只会排出其中的一部分——比如说半盎司。仅仅一千次心跳（对普通人来说大约是十五分钟）就能排出近四加仑的血液，远远超过人体血液总量。如果按重量而不是体积计算，心脏每天泵出的血液将超过一吨。这需要大量的食物摄入和运动。

The Galenists had an answer: both kinds of blood were constantly created from the ingestion of food and depleted in the growth and locomotion of the body. Harvey decided to do the math. From his dissections he had found that the left ventricle is capable of holding two ounces or more of blood, only a portion of which—say, half an ounce—is expelled on each beat. In just one thousand heartbeats (fifteen minutes for an average person) that would come to almost four gallons, far more blood than was present in the entire body. Reckoning by weight instead of volume, the heart would pump well over a ton of blood a day. That would require a lot of eating. And exercise.

于是，一个激进的假设出现了：当心脏左侧泵出的血液到达动脉末端时，它会被静脉接走并返回心脏右侧。换句话说，血液是循环流动的。

So came the radical hypothesis: when blood pumped by the left side of the heart reached the very ends of the arteries, it was picked up by the veins and returned to the right side of the heart. Blood, in other words, moved in a circle. It circulated.

他用一个精妙的实验证明了自己的观点。

He clinched his case with a beautiful experiment.

如果将一条活蛇剖开，可以看到它的心脏在一个多小时内安静而清晰地搏动，像蠕虫一样蠕动，纵向收缩（因为它的形状是长方形的），并推动其内容物。在收缩期，心脏颜色变浅；在舒张期，心脏颜色变深。

If a live snake be laid open, the heart will be seen pulsating quietly, distinctly, for more than an hour, moving like a worm, contracting in its longitudinal dimensions (for it is of an oblong shape), and propelling its contents. It becomes of a paler colour in the systole, of a deeper tint in the diastole.

用镊子或拇指和食指捏住下腔静脉，就在它进入心脏之前。阻塞部位下游的空间血液迅速流出。心脏颜色变浅，体积缩小，跳动也变慢，“仿佛最终就要停止跳动”。松开捏住的手指，心脏重新充满血液，恢复跳动。

Using a forceps or thumb and finger, pinch the main vein, the vena cava, just before it enters the heart. The space downstream from the obstruction quickly empties of blood. The heart grows paler and smaller, beating more slowly, “so that it seems at length as if it were about to die.” Release the grip and the heart refills with blood and springs back to life.

接下来，在主动脉离开心脏后立即将其夹住或结扎。可以看到阻塞物上游的空间“异常扩张，呈现深紫色甚至青紫色，最终被血液严重挤压，仿佛即将窒息”。同样，当阻塞物被清除后，心脏就会恢复正常。

Next pinch or tie off the main artery just after it leaves the heart. The space upstream from the obstruction is seen to become “inordinately distended, to assume a deep purple or even livid colour, and at length to be so much oppressed with blood that you will believe it about to be choked.” Again, when the blockage is removed the heart returns to normal.

案件本应就此结束。

Case closed, or so it should have been.

至于如何用显微镜观察人体四肢末端连接动脉和静脉的微小毛细血管，以及如何解释血液通过渗透作用跨越血管的机制，就留给其他人来解答了。与此同时，哈维为那些心存疑虑的人提供了一种自行验证他理论的方法。在你的上臂缠上一条绷带。绷带上方，靠近心脏一侧的动脉会搏动并肿胀。绷带下方，靠近手的一侧则不会搏动。与此同时，前臂的静脉会充满滞留的血液，而上方的静脉则会变得松弛。稍微放松绷带，使其刚好足以阻断静脉但又不阻断动脉。然后，感受血液迅速涌回你的手部。

It would be left for others to show with a microscope the tiny capillaries that, in the body’s extremities, connected the arteries to the veins, and to explain the osmotic process that carried the blood across the divide. Meanwhile Harvey offered doubters a means of confirming his theory for themselves. Place a tight bandage on your upper arm. Above the bandage, on the side toward the heart, the artery will throb and swell. Below it, toward the hand, there will be no throbbing. At the same time the veins in the lower arm will fill with trapped blood, as the ones above become flaccid. Loosen the bandage slightly, so that it is just tight enough to block off the veins but not the arteries. Then feel the mad rush of blood back to your hand.

然而，几乎没人相信他。多年以后，他仍在为自己的理论辩护，对抗“诋毁者、哗众取宠者和被污蔑的作家”。他哀叹道，他们像狂吠的恶犬一样纠缠着他，“但要小心，别让他们的疯狂情绪感染或感染他，也别让他们的恶犬用牙齿啃噬真理的根基。”

Still, hardly anyone believed him. Years later, he was still defending his theory against “detractors, mummers, and writers defiled with abuse.” They hounded him like barking dogs, he lamented, “but care can be taken that they do not bite or inoculate their mad humours, or with their dogs’ teeth gnaw the bones and foundations of truth.”

1642年，英国爆发内战，哈维凭借其与王室的联系，不幸落入战败一方。他的住所遭到洗劫，大部分科学论文也被毁。与国王不同，他幸免于难，并在十五年后去世，留下了一笔丰厚的遗产。他的朋友奥布里回忆说：“他常说，在他遭受的所有损失中，最令他痛彻心扉的莫过于这些论文的遗失，无论付出多少金钱，他都再也无法找回或获得它们。”

In 1642, when the English civil war broke out, Harvey, with his royal connections, found himself on the losing side. His home was ransacked and most of his scientific papers destroyed. He survived the turmoil, unlike his king, and died fifteen years later, a wealthy man. “But he often sayd, That of all the losses he sustained,” his friend Aubrey remembered, “no greife was so crucifying to him as the losse of these papers, which for love or money he could never retrieve or obtaine.”

血管，出自哈维的《心脏运动》

Blood vessels, from Harvey’s Motion of the Heart

第三章

CHAPTER 3

艾萨克·牛顿

Isaac Newton

什么是颜色

What a Color Is

艾萨克·牛顿，戈弗雷·内勒爵士，1689 年

Isaac Newton, by Sir Godfrey Kneller, 1689

事实上，自然科学长期以来一直沦为头脑和想象力的产物：现在是时候回归对物质和显而易见的事物进行观察的朴实和严谨了。

The truth is, the Science of Nature has been already too long made only a work of the Brain and the Fancy: It is now high time that it should return to the plainness and soundness of Observations on material and obvious things.

——罗伯特·胡克，《显微图谱》

—Robert Hooke, Micrographia

当你走进艾萨克·牛顿的陵墓，目光便会被拱形大理石天花板的巨大弧形空间和支撑它不至于因重力而坍塌的粗壮立柱所吸引。同样沉重的还有寂静，只有你拾级而上，走向这位科学家骨灰瓮的脚步声打破了这片沉寂。

AS YOU enter the tomb of Isaac Newton, your gaze is swept upward by the vast curved spaces of the vaulted marble ceiling and the massive supporting columns that keep it from succumbing to gravity. Weighing just as heavily is the silence, broken only by the echo of your footsteps ascending the stairs toward the scientist’s urn.

这时你就会注意到那束光。它从离地面大约二十英尺高的一个小孔射入，斜向下射，然后从安装在精美支架上的镜子上反弹。之后，它穿过房间，经过棱镜，最终变成自然界中常见的琶音：红、橙、黄、绿、蓝、靛、紫。

It will be then that you notice the light beam. Entering through a tiny hole, perhaps twenty feet above the floor, it shoots down at an angle and ricochets off a mirror mounted on an ornate stand. From there it travels across the room, through a prism, and is transformed into the familiar arpeggio that manifests itself in nature: red, orange, yellow, green, blue, indigo, and violet.

这幅画作描绘了牛顿的诸神，它仅存在于威尼斯艺术家乔瓦尼·巴蒂斯塔·皮托尼于1729年完成的《艾萨克·牛顿爵士寓言纪念碑》中，当时距离牛顿去世不久。（牛顿实际上安葬在威斯敏斯特教堂。）这幅画对于皮托尼来说可谓是一次风格上的突破，他更擅长宗教和神话题材的作品（例如《圣家族》和《波吕克塞娜的献祭》）。但它在另一个方面也显得不同寻常。

This pantheon exists only in a painting, An Allegorical Monument to Sir Isaac Newton, completed by the Venetian artist Giovanni Battista Pittoni in 1729, not long after Newton died. (He is actually buried in Westminster Abbey.) It was something of a departure for Pittoni, who is better known for religious and mythological themes (The Holy Family, The Sacrifice of Polyxena). But it was also unusual in another way.

牛顿（与莱布尼茨一起）因发明微积分——“流数法”——而名垂青史。微积分解释了伽利略一直未能理解的一个概念：加速运动的物体如何在无数个无穷小的瞬间中以无穷小的速度加速。在他后来的杰作《自然哲学的数学原理》中，他描述了天体的运动，并证明了使苹果下落的引力同样也使行星围绕太阳运行。但皮托尼的画作所颂扬的并非牛顿作为理论家和定律制定者的形象，而是作为实验家的形象。

Newton would become known to the ages (along with Leibniz) for his invention of calculus—the “method of fluxions”—which made sense of a concept that had eluded Galileo: how an accelerating object becomes infinitesimally faster during each of an infinity of infinitesimal moments of time. In his later triumph, the Principia Mathematica, he described the motions of the heavens and showed that the same gravity that causes an apple to fall holds the planets around the sun. But Pittoni’s painting was celebrating something different—not Newton the theorist, giver of laws, but Newton the experimenter.

艾萨克·牛顿爵士的寓言纪念碑，乔瓦尼·巴蒂斯塔·皮托尼绘制

An Allegorical Monument to Sir Isaac Newton, by Giovanni Battista Pittoni

他刚从剑桥大学三一学院毕业不久（1665年），大瘟疫就迫使人们迁往乡下。他被困在伍尔索普的家族农场里，把自己关在书房里，思考数学和运动方面的一些想法，并琢磨色彩和光线的奇特之处。

He was barely out of school, having graduated from Trinity College, Cambridge, in 1665, when the Great Plague forced an exodus to the countryside. Trapped at the family farm in Woolsthorpe, he closeted himself in his study, working out some ideas about mathematics and motion and contemplating the peculiarities of color and light.

柏拉图和一些前苏格拉底哲学家认为，光束从眼睛中发出，像探照灯一样扫视世界。亚里士多德否定了这种观点，他认为颜色是光与暗的混合。毕竟，黄色接近白色，蓝色接近黑色。到了牛顿时代，人们对颜色的认识逐渐清晰，哲学家们也开始发展出一门精确的光学科学。

Plato and some of the Presocratics believed that light beams emanated from the eyes, sweeping the world like searchlights. Aristotle, who rejected that idea, taught that colors are a mixture of light and darkness. Yellow, after all, is nearly white, and blue is almost black. By Newton’s time a clearer picture was emerging, and philosophers were developing a precise science of optics.

人们已经了解到，当光线照射到镜子上时，入射角等于反射角。当光线穿过透明介质并返回空气时，会发生弯曲或折射——这就是为什么当你踏入水池时，你的腿看起来像断了一样。折射的程度可以通过后来被称为斯涅尔定律的理论来预测。法国哲学家兼科学家勒内·笛卡尔在研究彩虹时，凝视着一个巨大的水滴——一个装满水的玻璃球——并研究了其中的颜色，这些颜色与肥皂泡、云母片、鱼鳞和昆虫翅膀在阳光下闪烁时所呈现的颜色非常相似。1637年，他在一篇名为《光学》的论文中试图解释颜色的起源，他推测颜色是由旋转的以太球产生的——旋转速度越快，光线就越红。

When light strikes a mirror, they had learned, the angle of incidence equals the angle of reflection. And when it passes through a transparent medium and back into the air, it is bent or refracted—that is why your leg looks broken when you step into a pool of water. The degree of the refraction could be predicted by something that became known as Snell’s law. While investigating rainbows, René Descartes, the French philosopher and scientist, had gazed into a giant droplet—a glass sphere filled with water—and studied the colors inside, so much like those that appeared when soap bubbles, flakes of mica, fish scales, and insect wings shimmer in the sunlight. In 1637, in an essay called Dioptrics, he tried to account for the origin of color, speculating that it was produced by spinning globules of aether—the faster the rotation, the redder the light.

但当时无人真正知晓。纯白光在与物质碰撞时，不知何故会沾染上颜色——当它照射到有色物体上反射，或穿过有色液体或玻璃时。笛卡尔之后的一代人中，欧洲三位最伟大的科学家——克里斯蒂安·惠更斯、罗伯特·波义耳和罗伯特·胡克——仍在提出各自的理论。他们中没有一个人会知道艾萨克·牛顿。尤其是胡克，他后来甚至希望自己从未听说过牛顿这个名字。

But no one really knew. Somehow pure white light became stained in its collisions with matter—when it bounced off a colored object or passed through a tinted liquid or piece of glass. A generation after Descartes three of Europe’s greatest scientists—Christiaan Huygens, Robert Boyle, and Robert Hooke—were still putting forth theories. None of them had any reason to know about Isaac Newton. Hooke, in particular, would come to wish he had never heard Newton’s name.

胡克身材矮胖，体态魁梧，但他对自然界的精妙操控却让他声名远扬，并成为伦敦皇家学会的首任实验馆长。当时，伦敦皇家学会正崛起为科学革命的中坚力量。作为最早的伟大显微镜学家之一，胡克绘制了大量精细的显微镜图谱——跳蚤和虱子被放大成巨大的怪物，霉菌的形态如同热带雨林中的花朵般奇特——这些图谱收录在他著名的著作《显微图谱》中。他将镜头聚焦在一块软木塞上，探索其中错综复杂的空腔，并首次将这些空腔称为“细胞”。胡克还是一位极富创造力的发明家，他设计了空气泵，并协助波义耳发现了气体体积与压力之间的反比关系，即波义耳定律。此外，还有一条胡克定律，它精确地描述了弹性的本质：固体的拉伸量与所受的力成正比。或者正如胡克本人所说，“ceiiinosssttuv”，它重新排列后是Ut tensio sic vis， “如延伸，则力亦如此”。（为了确立优先权并避免知识产权被窃取，他最初将该法律以拉丁文字母重组的形式发表。）

A stooped troll of a man, Hooke was so well known for his elegant manipulations of nature that he served as the first curator of experiments for the Royal Society of London, which was beginning its emergence as a powerhouse of the scientific revolution. One of the first great microscopists, Hooke produced meticulous drawings—a flea and a louse magnified into monsters, molds as extravagant as flowers in a tropical rain forest—that filled the pages of his celebrated book Micrographia. Focusing his lenses on a piece of cork, he explored the labyrinth of empty chambers and was the first to call them cells. An ingenious inventor, he designed an air pump and assisted Boyle in discovering the inverse relationship between the volume and pressure of a gas, Boyle’s law. There is a Hooke’s law as well, precisely describing the nature of elasticity: the amount a solid object can be stretched is proportional to the force that is applied. Or as Hooke himself put it, “ceiiinosssttuv,” which unscrambles into Ut tensio sic vis, “As the extension, so the force.” (To establish priority and avoid intellectual property theft, he first published the law as a Latin anagram.)

在显微镜下观察，“一小块白色的毛状霉菌”。（引自罗伯特·胡克，《显微图谱》）

Viewed under a microscope, “a small white spot of hairy mould.” From Robert Hooke, Micrographia

胡克确信自己也弄清了颜色和光的奥秘。白色是根本，而其他颜色都是偏差：“蓝色是视网膜上对一束倾斜且混乱的光脉冲的印象，其最弱的部分在前，最强的部分在后，”他晦涩地写道。红色则相反——一种畸形的光脉冲，“其最强的部分在前，最弱的部分在后”。红色和蓝色可以混合稀释，形成各种杂乱的色调。惠更斯和波义耳也有各自的理论，但他们的理论最终都归结于同一个基本原理——颜色是光的色散。

Hooke was certain he had also figured out color and light. White was fundamental, and colors were aberrations: “Blue is an impression on the Retina of an oblique and confus’d pulse of light, whose weakest part precedes, and whose strongest follows,” he obscurely wrote. Red was the opposite—a misshapen pulse “whose strongest part precedes, and whose weakest follows.” Red and blue could be mixed and diluted to form mongrel hues. Huygens and Boyle had their own theories, but they all came down to the same bedrock—color as stained light.

从零开始，牛顿仔细回顾了前人的发现，并补充了自己的观察。一片薄到几乎透明的金箔会反射黄光。但他注意到，如果将金箔“与眼睛和蜡烛交叉”，透过金箔的光就会变成蓝色。一种名为肾木（lignum nephriticum）的木材则会产生相反的效果，这种木材被药剂师当作肾脏治疗药物出售。当肾木被切成薄片并浸泡在水中时，“（在透明紫罗兰色的紫罗兰色紫罗兰色紫外光下观察）溶液会反射蓝色光线，透射黄色光线。”某些平板玻璃也是如此：它们“从正面看是一种颜色，从背面看又是另一种颜色。”但这些都是像差。“通常情况下，物体从正面看呈现任何颜色，从任何角度看都呈现相同的颜色。”

STARTING from scratch, Newton carefully reviewed what others before him had found and added some observations of his own. A piece of gold leaf, thin enough to be almost transparent, reflects yellow light. But hold it “twixt your eye & a candle,” he noted, and the light passing through is blue. The opposite effect could be had from a wood called lignum nephriticum, sold by druggists as a kidney treatment. When it was sliced into thin pieces and infused in water “the liquor (looked on in a cleare violl) reflects blew rays & transmits yellow ones.” The same was true for certain pieces of flat glass: they “appeare of one colour when looked upon & of another colour when looked through.” But these were aberrations. “Generally bodys which appeare of any colour to the eye, appeare of the same colour in all positions.”

他与世隔绝，远离瘟疫，如同盲人重见光明一般，用全新的视角审视着这个世界。深色或半透明的物质被磨成粉末或用刀削成薄片后，颜色会变浅——因为这种碾碎的过程会创造出原本不存在的“大量反射面”。相反，浸泡在水中的物质颜色会变深，“因为水会填满反射孔隙”。

Shut away from the plague, he studied the world with the eyes of a blind man suddenly able to see. Dark or translucent substances ground into a powder or shaved with a knife become lighter in appearance—for the mangling creates a “multitude of reflecting surface” that didn’t exist before. By contrast substances soaked in water become darker, “for the water fills up the reflecting pores.”

他还摆弄玻璃板，将一块平面透镜像三明治一样夹在一块弧度柔和的球面透镜上。用光束照射表面，他看到了令人着迷的彩色漩涡图案，这就是牛顿环。“因此，随着玻璃板压得更紧或更松，彩色圆圈的大小也会随之变化。而且，随着压得越来越紧，新的圆圈会在中间出现。”他把装置带进暗室，用棱镜发出的蓝光照射。这一次，他看到的是一个由明暗圆圈组成的单色图案。红光也产生了类似的图案。

He also played with plates of glass, mounting a flat lens sandwichlike against one with a gentle spherical curve. Shining a light beam at the surface he beheld a mesmerizing pattern of colorful swirls. Newton’s rings. “Accordingly as the glasses are pressed more or lesse together the coloured circles doe become greater or less. & as they are pressed more & more together new circles doe arrive in the midst.” Taking the apparatus into a dark room he exposed it to a blue ray emitted by a prism. This time he saw a monochromatic target of dark and light circles. Red light produced a similar pattern.

胡克在《显微图谱》中已经描述过干涉现象，但牛顿深入研究了它，并将其据为己有。

Hooke had already described the phenomenon—interference—in Micrographia, but Newton plumbed its depths and made it his own.

用透镜夹层结构来展示牛顿环

A lens sandwich used to show Newton’s rings

随着兴趣渐浓，他甚至开始用自己的眼睛做实验。他取了一根细而钝的探针——他称之为“锥子”——小心翼翼地将其插入“眼球和眼眶之间，尽可能靠近眼球后壁”。他用这根探针按压并摩擦眼球，看到了“几个白色、深色和彩色的圆圈”。当他在日光下重复这个实验，几乎闭上眼睛时，“出现了一个宽阔的深蓝色圆圈”，里面还有一个较小的浅色斑点。如果他用力按压，那个斑点里还会出现另一个蓝色的小圆圈。在黑暗中进行实验则产生了不同的效果：“圆圈看起来像是泛着红光”，围绕着一个“深蓝色”的内圈。

As his interests grew into an obsession, he even experimented with his own eyes, taking a thin, blunt probe—a bodkin, he called it—and carefully inserting it “betwixt my eye & the bone as neare to the Backside of my eye as I could.” Pressing and rubbing the instrument against his eyeball, he saw “severall white darke & coloured circles.” When he repeated the experiment in daylight, with his eyes almost closed, “There appeared a greate broade blewish darke circle” with a smaller, lighter spot inside. If he pressed hard enough, within that spot was another little circle of blue. Performing the experiment in darkness produced a different effect: “the circle apeared of a Reddish light” surrounding an inner circle of “darkish blew.”

有时，当他在眼眶里摸索时，他会察觉到更细微的差别：一个由彩色圆环组成的靶子，“从中心开始依次是：绿色、浅色、紫色、深紫色、浅色、绿色、黄色、火焰般的红色、黄色、绿色、浅色、宽紫色、深紫色。” 当他凝视太阳或其倒影时，他注意到残影是红色的，“但如果我走进一个黑暗的房间，幻影就会变成浅色的。”

Sometimes as he poked around in his eye socket he perceived still finer distinctions: a target of colorful rings “from the center greene, blew, purple, darke purple, blew, greene, yellow, red like flame, yellow, greene, blew, broade purple, darke.” Staring at the sun or its reflection, he noticed that the afterimage was red, “but if I went into a dark roome the Phantasma was blew.”

他偶尔会从物理学转向解剖学。他从阅读中了解到，视觉振动从每只眼睛经由视神经——“无数细长的管道”——传递到大脑。他解剖了眼睛周围的组织——谢天谢地，是动物的，而不是他自己的——试图确定承载图像的物质的性质。“水太粗糙了，无法传递如此微妙的印象，”他得出结论。盖伦学派所说的在神经系统中流动的“动物精气”似乎更有可能。牛顿通过一个实验排除了这种可能性：“我把一段视神经的一端绑起来，然后加热中间部分，看看是否会有某种气态物质在另一端以气泡的形式显现出来，但我连一个气泡都没看到；只有一点点水分，骨髓就被挤出来了。”

From physics he occasionally detoured into anatomy. From each eye, he learned in his readings, the visual vibrations traveled through the optic nerves—“a vast multitud of these slender pipes”—and into the brain. Dissecting the tissues around an eye—an animal’s, thank God, not his own—he tried to determine the nature of the substance that carried the imagery. “Water is too grosse for such subtile impressions,” he concluded. A better possibility seemed to be the “animal spirits” said by the Galenists to blow through the nervous system. Newton ruled that out with an experiment: “though I tyed a peice of the optick nerve at one end & warmed it in the middle to see if any aery substance by that meanes would disclose it selfe in bubbles at the other end, I could not spy the least bubble; a little moisture only & the marrow it selfe squeezed out.”

牛顿用自己的眼睛做实验：摘自他的笔记

Newton’s experiment with his own eye: a page from his notebooks

如果一切就此止步——等待视觉之灵从视管中涌现——牛顿或许只会是十七世纪众多被光所迷惑和吸引的天才之一。但在他的研究过程中，他突然对棱镜产生了浓厚的兴趣。在一张黑纸上画一条线，一半是蓝色，一半是“深红色”，棱镜会使这条线看起来歪斜：“颜色之间断成了两截”。同样的情况也发生在蓝线和红线之间。一条线与另一条线的位置发生了偏移。但为什么棱镜对这两种颜色的处理方式不同呢？

If that is where it all had ended—waiting for the spirits of vision to come bubbling from the optic tubules—Newton might have remained just another seventeenth-century genius confused and tantalized by light. But sometime in the midst of his investigations he became captivated by a curiosity involving prisms. Draw a line, half blue and half a “good deepe red,” on a black piece of paper and the prism will make it appear skewed: “broken in two twixt the colours.” The same thing happened with blue and red threads. One was offset from the other. But why were the colors treated differently by the glass?

有一天，他出于好奇，在百叶窗上剪了一个直径约四分之一英寸的小圆孔。他把棱镜对准阳光穿过的狭窄路径，在黑暗房间的远处墙上投射出一道光谱。

One day, his curiosity aroused, he cut a small circular hole a quarter-inch across in his window shutter. Holding a prism in the narrow path of the sunbeam, he cast a spectrum on the far wall of the darkened room.

“起初，欣赏那些鲜艳浓烈的色彩真是一种令人愉悦的消遣，”他写道：蓝色逐渐过渡到绿色，然后黄色又过渡到橙色和红色。但比光谱的常见外观更重要的是它的形状。它不像快门上的孔或太阳的影像那样是圆形的，而是长方形的：长十三又四分之一英寸，宽二又五分之八英寸。这种“比例失调如此惊人，激起了我非同寻常的好奇心，想要探究它究竟源自何处。”

“It was at first a very pleasing divertisement to view the vivid & intense colours,” he reported: blues fading into greens then yellows into oranges and reds. But far more significant than the familiar appearance of a spectrum was its shape. It was not circular like the hole in the shutter or the image of the sun, but oblong: thirteen and one-fourth inches long, two and five-eighths inches wide. It was “a disproportion soe extravagant that it excited me to a more then ordinary curiosity of examining from whence it might proceed.”

牛顿画的他的十字架实验

Newton’s drawing of his Experimentum Crucis

某种因素导致颜色以这种方式扩散开来。牛顿怀疑这种现象可能是人为造成的，是一些偶然因素共同作用的结果。但他必须排除这种可能性。他尝试将棱镜放在不同的位置，让光线“穿过不同厚度的玻璃片”。他在棱镜上开了“大小不一”的孔。他还尝试将棱镜放在窗外，让阳光在穿过孔之前照射到棱镜上。但所有这些尝试都无济于事。“在所有这些情况下，颜色的分布方式都是一样的。”

Something was causing the colors to fan out this way. Newton doubted that the effect could be an artifact, some obscure confluence of accidental effects. But the possibility had to be ruled out. He tried holding the prism in different positions so that the light traveled “through parts of the glasse of divers thicknesses.” He cut holes in the shade of “divers bignesses.” He tried putting the prism outside the window, so the sunlight hit it before passing through the hole. None of that mattered. “The fashion of the colours was in all these cases the same.”

他用一个棱镜折射阳光后发现，如果让这些颜色的光通过第二个棱镜，它们就会重新组合。第二个棱镜抵消了第一个棱镜的作用，在墙上留下了一个无色的光圈。这些颜色并非棱镜添加的，它们一直都存在于光束中。

Having refracted sunlight with one prism, he found that he could pass the colors through a second prism and they would recombine. The second prism undid what the first had done, leaving a colorless circle of light on the wall. The colors were not added by the prism. They had been in the light beam all along.

正是无数这样的实验最终让他得出了令人惊讶的结论。当他准备进行他后来称之为“十字架实验”（借用胡克的说法）的实验时，他或许已经预料到了会发现什么。但这丝毫没有减损实验的戏剧性。和之前一样，从窗户射出的光束穿过棱镜，照射到房间里，但这一次，它的光谱投射到一块木板上。牛顿在木板的一端钻了一个孔，通过巧妙地调整棱镜的位置，他可以让各种颜色的光依次穿过这个孔。然后，这些光进入第二个棱镜，最终在墙上留下图像。

It was a multitude of such experiments that led him to his surprising conclusion. By the time he was ready for what he would call his Experimentum Crucis (borrowing the term from Hooke), he probably knew what he would find. But that barely detracts from the drama. As before, the light beam from the window passed through a prism and crossed the room, but this time it cast its spectrum on a wooden board. Through one end of the board Newton had drilled a hole, and by holding his prism just so, he could make the colors pass through the opening one by one. From there they entered a second prism before leaving an image on the wall.

他那天所看到的景象彻底改变了我们对光的认知。从光谱的红色端开始，向蓝色端推进，每种颜色的光线都略微弯曲——这正是彩色丝线所暗示的效应的进一步阐释：“蓝色光线比红色光线折射得更厉害。” 这就是光谱呈椭圆形的原因。如果所有颜色的折射程度相同，光谱就会呈现圆形。但正如牛顿所说，光“是由折射率不同的光线组成的”。

What he saw that day changed forever how we think about light. Starting at the red end of the spectrum and progressing toward the blue, each color was bent a little more—an elaboration of the effect hinted at by the colored threads: “blew rays suffer a greater refraction than red ones.” That was the reason for the oblong. If all colors were bent equally the spectrum would be a roundish blob. But light, as Newton put it, “consists of rayes differently refrangible.”

易折射的（Refrangible）意为可折射的——这两个词都源自同一个拉丁词根——而牛顿发现的正是颜色的本质：一束光线具有超自然的折射特性。“同一种颜色总是对应着相同的折射程度，同一种颜色也总是对应着相同的折射程度，”他写道。颜色即折射性。

Refrangible means refractable—both words come from the same Latin root—and Newton had discovered nothing less than what a color is: a ray of light preternaturally disposed to bend a certain way. “To the same degree of refrangibility ever belongs the same colour, & to the same colour ever belongs the same degree of refrangibility,” he wrote. Color is refrangibility.

还有更多。一旦某种颜色与其他颜色分离出来，无论他如何努力，都无法再改变它。“我用棱镜折射它，用日光下呈现其他颜色的物体反射它；我用夹在两块压缩玻璃板之间的彩色空气膜截取它，让它穿过有色介质和照射过其他光线的介质，并尝试各种不同的方法，但仍然无法从中产生任何新的颜色。它会因为收缩或扩张而变得更鲜艳或更暗淡，在某些情况下，由于失去许多光线而变得非常模糊和黑暗，但我始终无法在肉眼中看到它的变化。”

And there was more. Once a color was separated from the rest, it could not be further altered, no matter how hard he tried. “I have refracted it with Prismes, & reflected it with bodies which in day light were of other colours; I have intercepted it with the coloured film of air interceding two compressed plates of Glasse, transmitted it through coloured mediums & through mediums irradiated with other sort of rayes, & diversly terminated it, & yet could not produce any new colour out of it. It would by contracting or dilating become more brisk or faint, & by the losse of many rayes in some cases very obscure & dark, but I could never see it changed in Specie.”

如果一束光线由多种颜色组成——例如橙黄色、黄绿色——它可以被棱镜再次分解，但最终会回到光的本质，也就是光的基本组成部分。“颜色并非如人们通常认为的那样，是由自然物体的折射或反射而产生的光的特性，而是光本身固有的属性。”

If a ray was composed of more than one color—orangish yellow, yellowish green—it could be split once again by a prism, but at some point you would reach the bottom, the fundamental components of light. “Colours are not qualifications of light derived from refractions or reflections of naturall bodies as ’tis generally beleived, but originall & connate properties.”

那道混杂的光芒是白光，它并非仅仅是一种颜色，而是所有颜色的混合体，是“不同折射率光线的异质混合物”。当阳光照耀大地时，它并非照亮苹果的红色、树叶的绿色。而是苹果和树叶从阳光中反射出色彩。

It was white light that was the mongrel, not just another color but a combination of them all, a “heterogeneous mixture of differently refrangible rayes.” As the sun shines on the world, it is not bringing out the red in an apple, the green in a leaf. The apple and the leaf are bringing the colors out of the sunlight.

笛卡尔也曾认为颜色并非物体固有的，而是物体对光线产生影响的结果。现在牛顿明白了其中的原因。世界之所以色彩斑斓，是因为它由各种物体构成，“这些物体反射某种光线的能力各不相同”。

Descartes had also believed that colors were not inherent in objects, but rather manifestations of how they affected light. Now Newton knew why. The world is colorful because it consists of bodies “variously qualified to reflect one sort of light in greater plenty than another.”

1666年9月初，伦敦大火肆虐，摧毁了伦敦的大部分地区，也杀死了老鼠，加速了鼠疫的结束。罗伯特·胡克暂时放下光学和其他科学研究，与克里斯托弗·雷恩一起重建这座城市。牛顿则回到剑桥，在那里他晋升为卢卡斯数学教授，并讲授色彩和光线方面的知识。他发明了一种反射望远镜，长六英寸，比十倍于其体积的传统望远镜还要强大，这给皇家学会的成员留下了深刻的印象。1672年，也就是他进行实验六年之后，皇家学会在《哲学汇刊》上发表了他的论文《关于光和颜色的新理论》。

IN EARLY September 1666, the Great Fire destroyed much of London, killing the rats and hastening the end of the plague. Setting aside optics and other scientific pursuits, Robert Hooke worked with Christopher Wren to rebuild the city. Newton moved back to Cambridge, where he rose to the position of Lucasian professor of mathematics and lectured on color and light. A reflecting telescope he invented, six inches long and more powerful than a conventional telescope ten times its size, impressed the members of the Royal Society, and in 1672, six years after his experiments, they published his paper “New Theory About Light and Colors” in the society’s Philosophical Transactions.

胡克嫉妒得发狂，试图诋毁这个后起之秀，由此引发了一场持续终生的恩怨。胡克宣称他自己已经做过所有这些实验，而且实验结果完全可以用他自己的理论来解释。（后来他又声称牛顿的《自然哲学的数学原理》抄袭了他的著作。）

Burning with jealousy, Hooke tried to discredit the upstart, setting off a feud that would last as long as both men were alive. Hooke declared that he had already performed all these experiments himself, and that the results could be explained just as well by his own theory. (Later he would claim that Newton’s Principia was plagiarized from him.)

其他科学家，如惠更斯，也在给期刊的信中提出了异议，牛顿则以怀疑和轻蔑的混合态度反驳这些反对者。对新思想的无情剖析将成为科学的常态。但牛顿生性极其注重隐私，他感到自己的尊严受到了侵犯。一群英国耶稣会士尤其令他恼火，他们坚持认为无法重复他的“十字架实验”，并声称光谱的扩散是由“明亮的云”造成的假象。这种吹毛求疵一直持续到1678年，最终他忍无可忍，隐居起来。那时他35岁，还有太多事情要做。

Other scientists, like Huygens, also raised objections in dispatches to the journal, and Newton countered his nay-sayers with a mixture of disbelief and scorn. The merciless dissection of new ideas would become a normal part of science. But Newton, an intensely private man, felt violated. He became especially agitated by a group of English Jesuits who insisted that they could not replicate his Experimentum Crucis and that the spreading out of the spectrum was an artifact caused by a “bright cloud.” The carping continued until 1678, when in exasperation he retreated into seclusion. He was thirty-five. There was so much still to be done.

第四章

CHAPTER 4

安托万-洛朗·拉瓦锡

Antoine-Laurent Lavoisier

农家女

The Farmer’s Daughter

安托万-洛朗·拉瓦锡

Antoine-Laurent Lavoisier

想象一下，了解是什么赋予树叶颜色！是什么让火焰燃烧！这其中的意义有多重大。

Imagine what it means to understand what gives a leaf its color! What makes a flame burn.

——玛丽·安妮·拉瓦锡在卡尔·杰拉西和罗尔德·霍夫曼创作的戏剧《氧气》中的台词

—Marie Anne Lavoisier in the play Oxygen, by Carl Djerassi and Roald Hoffmann

1772年秋日的一天，在卢浮宫外的王子花园，漫步塞纳河畔的巴黎人或许会注意到一个奇特的装置：一个六轮木平台，形似平板马车，上面架设着一组巨大的玻璃片。其中两片最大的透镜——半径达八英尺——被巧妙地组合成一个强大的放大镜，用于捕捉太阳光线，并通过第二片较小的透镜将其投射到桌面上。在平台上，戴着假发和墨镜的科学家们正在进行实验，而助手们则像海军学员一样，摇动齿轮、调整索具，随着太阳在天空中的移动而调整方向。

OUTSIDE the Louvre in the Jardin de l’Infante on an autumn day in 1772, Parisians strolling along the Seine might have noticed a strange contraption: a wooden platform on six wheels, like a flatbed wagon, on top of which was mounted an assembly of enormous pieces of glass. The two largest lenses—eight feet in radius—had been sandwiched into a single powerful magnifier that captured the solar rays, beaming them through a second, smaller lens and onto a table. Standing on deck, scientists in wigs and dark glasses were performing an experiment, while assistants, like midshipmen, cranked gears and adjusted the rigging, following the sun across the sky.

当时预定使用这台机器（当时的粒子加速器）的人之一是安托万-洛朗·拉瓦锡。他试图弄清楚焚烧钻石会发生什么。

One of the men who had booked time on the machine—the particle accelerator of its day—was Antoine-Laurent Lavoisier. He was trying to find out what happens when you incinerate diamonds.

人们早就知道钻石会燃烧（我们现在知道钻石是由碳构成的），当地的珠宝商曾请求法国科学院调查这是否会造成危险。拉瓦锡本人则对另一个问题更感兴趣：燃烧的化学本质。“燃烧玻璃”的妙处在于，它可以将阳光聚焦到封闭容器内的某一点，加热容器内的物体。然后，容器中产生的烟雾可以通过导管导入装有水的烧瓶，冒出气泡，取出进行分析。

It had long been known that diamonds burn (we now know that they are made of carbon), and local jewelers had asked the French Academy of Science to investigate whether this posed a risk. Lavoisier himself was more interested in another question: the chemical nature of combustion. The beauty of the “burning glass” was that it could focus sunlight onto a spot inside a closed container, heating whatever had been placed inside. The fumes from the jar could then be channeled through a tube into a flask of water, gurgling up to form a bubble to be drawn off and analyzed.

钻石焚烧

Incinerating diamonds

实验失败了：高温不断使玻璃破裂。但拉瓦锡还有其他计划。他向科学院提出的方案是研究“物质中所含的空气”及其与火的本质之间的联系。

The experiment was a failure: the intense heat kept cracking the glass. But there were other items on Lavoisier’s agenda. What he had proposed to the Academy of Science was a program to study “the air contained in matter” and how it might be related to the true nature of fire.

尽管牛顿使物理学走上了一条更为笔直的道路，但他对化学的贡献却不大，化学仍然深受炼金术的影响。“将樟脑溶于充分脱脂的硝石酒精中，会得到无色溶液，”他写道。“但如果将其倒入上等硫酸中，并在樟脑溶解的同时摇晃，溶液会先呈黄色，然后变成深红色。”在这本烹饪化学手册中，几乎从未提及测量或量化：“将盐酒滴入新鲜尿液中，两种液体会迅速而平静地混合，”他写道，“而如果将同样的酒滴入消化过的尿液中，很快就会发出嘶嘶声并沸腾，挥发性酸性盐过一会儿会凝结成第三种物质，有点像萨拉莫宁。紫罗兰糖浆溶于少量新鲜尿液中只会稀释，而几滴发酵过的尿液却会立即将其变成深绿色。”

ALTHOUGH Newton had put physics on a straighter path, he hadn’t been much help with chemistry, which was still in the thrall of alchemy. “Camphire dissolved in well deflegmed spirit of niter will make a colourlesse solution,” he had written. “But if it bee cast into good Oyle of Vitriol & shaken into it as it dissolves, the liquor will bee first yellow & then of a deepe reddish colour.” In page after page of this cookbook chemistry, there was little talk of measurement or quantification: “Putting spirit of salt to fresh urin the two liquors readily & quietly mix,” he noted, while “if the same spirit be dropped upon digested urin there will presently ensue a hissing & ebullition, & the volatile & acid salts will after a while coagulate into a third substance, somewhat of the nature of Salarmoniac. And whereas the syrup of Violets is but diluted by being dissolved in a little fresh urin, a few drops of fermented urin presently turns it into a deep green.”

至少，那是化学的雏形。炼金术的许多内容，包括牛顿自己的炼金术，在现代人听来都像是魔法。在他的一本笔记本中，他忠实地抄录了一位名叫乔治·斯塔基（George Starkey）的炼金术士的段落，此人自称菲拉莱特斯（Philalethes）。

That, at least, was protochemistry. Much of alchemy, including Newton’s own, sounds to modern ears like magic. In one of his notebooks, he had dutifully copied passages from an alchemist named George Starkey, who called himself Philalethes.

“土星之中隐藏着不朽的灵魂，”这段文字开头写道。土星通常代表铅——每种元素都与一颗行星产生共鸣——但在这里，它显然指的是一种名为锑的银白色金属。“不朽的灵魂”是矿石暴露在烈焰中时释放出的气体。“火星与土星以爱的纽带相连”——铁被加入到锑中——“火星被土星吞噬，其精神分裂了土星的躯体，两者结合后流淌出奇妙的明亮之水，太阳在其中落下，散发光芒。”太阳是金属黄金，在这里它浸没在水银（俗称水银）中。“金星，一颗最闪亮的恒星，被火星拥抱。”金星是铜。现在它也被加入其中。这套冶金配方显然描述了人们梦寐以求的“贤者之石”的早期生产过程，这种石头能够将低等元素转化为黄金。

“In [Saturn] is hid an immortal soul,” the passage began. Saturn usually meant lead—each element resonated with a planet—but here it apparently refers to a silvery metal called antimony. The “immortal soul” is the gas emitted when the ore is exposed to an intense flame. “To Saturn Mars with bonds of love is tied”—iron is added to antimony—“who is by him devourd of mighty force whose spirit divides saturns body & from both combined flow a wondrous bright water in which ye Sun doth set & loos its light.” The sun is metallic gold, and here it is immersed in mercury, commonly called quicksilver. “Venus a most shining star is embract’d by [Mars].” Venus was copper. Now it too was added to the mix. The metallurgical recipe is apparently a description of the early stages of producing the long-sought “philosopher’s stone,” capable of transmuting baser elements into gold.

拉瓦锡和他的同僚们早已超越了这种神秘的咒语，但化学家们仍然普遍接受炼金术的观点，即物质由三种元素支配：汞（使物质呈液态）、盐（使物质呈固态）和硫（使物质燃烧）。硫磺之灵，也被称为“油土”（ terra pingua），尤其令人着迷。18世纪初，德国化学家格奥尔格·恩斯特·施塔尔将其重新命名为燃素（phlogiston），源自希腊语词根phlog，意为“火”。

Lavoisier and his peers had moved beyond such mystical incantations, but chemists still commonly accepted the alchemical notion that matter was governed by three principles: mercury (which made things liquid), salt (which made them solid), and sulfur (which made them burn). The sulfurous spirit, also called terra pingua (“fat” or “oily” earth) was a special source of fascination. Early in the 1700s, a German chemist, Georg Ernst Stahl, renamed it phlogiston from the Greek root, phlog, referring to fire.

物体之所以会燃烧，是因为它们富含燃素，燃烧过程中会将这种易燃物质释放到空气中。点燃一块木头，只有当其中的燃素耗尽时，它才会停止燃烧，留下一堆灰烬。由此推断，木头是由燃素和灰烬构成的。同样地，用烈火加热金属（称为煅烧）会留下一种白色易碎的物质，即氧化钙。因此，金属也是由燃素和氧化钙构成的。生锈是这种缓慢燃烧的另一种形式，呼吸作用也是如此——都是由于燃素释放到空气中而引起的反应。

The reason things burned was that they were rich in phlogiston, and as they were consumed they released this fire stuff into the air. Set a piece of wood aflame and it would stop burning only when its phlogiston was spent, leaving behind a pile of ash. Wood, it logically followed, was made of phlogiston and ash. Likewise, heating a metal under an intense flame, a process called calcination, left a whitish brittle substance, or calx. Metal was thus composed of phlogiston and calx. Rusting was another form of this slow combustion, as was respiration—reactions caused when phlogiston is given up to the air.

这个过程反过来也成立。人们发现，氧化钙与从地下开采出来的粗矿石非常相似，而将粗矿石放在木炭旁加热，可以提炼或还原——也就是“活化”。木炭会释放出燃素，燃素与氧化钙结合，从而回收出这种有光泽的金属。

The process also worked the other way around. Calx, it was recognized, resembled the crude ores mined from the ground, which were refined or reduced—“revivified”—by heating them next to a piece of charcoal. The charcoal emitted phlogiston, which combined with the calx to recover the lustrous metal.

引入一个无法测量、只能推断的假想实体，本身并没有什么错。在当今时代，宇宙学家提出，必然存在一种无形的“暗物质”，它阻止星系因自身的离心力而分离；同时，一种反引力的“暗能量”推动着宇宙的膨胀。

There was nothing necessarily wrong with invoking a hypothetical entity that could not be measured but only inferred. In our own time, cosmologists propose that an intangible “dark matter” must exist to keep the galaxies from spinning apart from their own centrifugal forces, and that an antigravitational “dark energy” propels the cosmological expansion.

有了燃素，科学家们就能对燃烧、煅烧、还原甚至呼吸作用做出一致的解释。化学突然变得清晰易懂了。

With phlogiston, scientists had a consistent explanation for combustion, calcination, reduction, and even respiration. Chemistry suddenly made sense.

然而，问题在于：煅烧后残留的氧化钙比原金属更重。去除燃素后，怎么会留下更重的东西呢？就像四分之一世纪后的暗能量一样，用法国哲学家孔多塞的话来说，燃素“受到某种力的驱使，使其运动方向与重力相反”。一位化学家更诗意地宣称，燃素“赋予了地球上的分子以翅膀”。

There was however a problem: the calx left behind after calcination weighed more than the original metal. How could removing phlogiston leave something heavier? Like dark energy a quarter of a millennium later, phlogiston was, in the words of the French philosopher Condorcet, “impelled by forces that give it a direction contrary to that of gravity.” Putting it more poetically, one chemist declared that phlogiston “gave wings to earthly molecules.”

拉瓦锡也逐渐认识到燃素是物质的主要成分之一。但在他进行钻石实验前后，他开始思考：为什么有些东西的重量会小于零呢？

Lavoisier too had learned to think of phlogiston as one of the principal ingredients of matter. But around the time of his experiments with diamonds he was beginning to wonder: How could something weigh less than zero?

他的母亲在他年幼时便去世了，留下了一笔足以让他入股一家名为“总农场”（Ferme Générale）的盈利企业。法国政府与这家由商人组成的私人财团签订合同，代其征收某些税款，并向像拉瓦锡这样的“农场主”支付分成。尽管他的公务占用了他大量的科研时间，但他仍然赚到了足够的钱，为自己配备了当时欧洲最好的实验室之一。1769年，他早期的一项实验旨在验证当时人们普遍认为的水可以变成土的说法。

HIS MOTHER had died when he was a boy, leaving an inheritance large enough for him to buy into a profitable enterprise called the Ferme Générale, or General Farm. The French government contracted with this private consortium of businessmen to collect certain taxes, giving the “farmers,” like Lavoisier, a cut. Though his duties took time away from research, he made enough money to equip himself with one of the best laboratories in Europe. One of his early experiments, in 1769, investigated the commonly held belief that water could turn into earth.

证据似乎很有说服力：水在锅中蒸发后会留下固体残渣。拉瓦锡用一种名为“鹈鹕瓶”的玻璃蒸馏瓶揭开了问题的本质。这种容器底部圆润肥厚，上部有一个小腔室，配有两根弯曲的管子（形状有点像鹈鹕的喙），可以将冷凝的蒸汽返回底部。对炼金术士来说，鹈鹕象征着基督的献祭之血，据说鹈鹕瓶具有转化能量。更重要的是，在鹈鹕瓶中煮沸的水会不断地蒸发和冷凝，而没有任何东西——无论是固体、液体还是气体——会离开这个系统。

The evidence seemed persuasive: water evaporating in a pan leaves behind a solid residue. Lavoisier cut to the heart of the matter with a glass distilling flask called a pelican. Round and fat at the base with a small upper chamber, the vessel was outfitted with two curving tubes (shaped a bit like pelican beaks) that returned condensed vapors to the bottom. To the alchemists, the pelican symbolized the sacrificial blood of Christ, and a pelican flask was said to have transformative powers. More to the point, water boiled in a pelican would continually evaporate and recondense without anything—solid, liquid, or gas—leaving the system.

鹈鹕烧瓶。约翰·弗伦奇，《蒸馏的艺术》（伦敦，1651年）

A pelican flask. John French, The Art of Distillation (London, 1651)

拉瓦锡连续一百天蒸馏纯水后，发现确实有残留物积聚。但他怀疑这些残留物的来源。他称量空鹈鹕瓶的重量，证实它比之前轻了。当他干燥并称量剩余的残渣时，重量与之前非常接近，这让他确信这些残渣来自玻璃。

After distilling pure water for a hundred days, Lavoisier found that a residue had indeed accumulated. But he suspected where it had come from. Weighing the empty pelican, he confirmed that it was lighter than before. When he dried and weighed the leftover debris, it matched closely enough to convince him that it had come from the glass.

两年后，即1771年，时年28岁的拉瓦锡与玛丽·安妮·皮埃雷特·保尔兹结婚，她是另一位包税人的女儿，年仅13岁。（她对这门婚事相当满意：她的另一位追求者已经50岁了。）玛丽·安妮被丈夫的研究深深吸引，便在他身边学习化学，记录笔记，将英文科学文献翻译成法文，并为一系列实验绘制了精细的图纸，其中最杰出的一项实验堪称完美，如同点石成金一般，将炼金术转化为化学。

Two years later, in 1771, Lavoisier, who was then twenty-eight, married Marie Anne Pierrette Paulze, the thirteen-year-old daughter of another tax farmer. (She was pleased enough with the arrangement: her other suitor was fifty years old.) Fascinated by her husband’s research, Marie Anne learned chemistry at his side, recording notes, translating English scientific literature into French, and producing the meticulous drawings for a series of experiments crowned by one so beautiful that—like a philosopher’s stone—it transformed alchemy into chemistry.

玛丽·安妮·皮埃雷特·保尔兹

Marie Anne Pierrette Paulze

拉瓦锡那一代的化学家们早已发现，正如英国人约瑟夫·普里斯特利所说，空气有“不同种类”。有毒的空气（或称“固定空气”）能熄灭火焰，也能使老鼠窒息。它还能使石灰水（现代术语为氢氧化钙）变浑浊，形成白色沉淀（碳酸钙）。但植物却能在这种气体中茁壮生长，并逐渐使空气再次变得适宜呼吸。

THE CHEMISTS of Lavoisier’s generation had already discovered that there were, as the Englishman Joseph Priestley put it, “different kinds of air.” Mephitic (meaning noxious), or “fixed air,” would extinguish a flame and suffocate a mouse. It also turned limewater (calcium hydroxide in modern terms) cloudy, forming a white precipitate (calcium carbonate). But plants thrived in the gas and slowly made it breathable again.

当蜡烛在带盖的罐子里燃烧时，还会产生另一种令人窒息的气体。这种气体不会析出石灰水，而且显然与燃烧有关，因此被称为“燃素气体”（phlogisticated air）——或称“ azote”，源自希腊语，意为“无生命”。最神秘的气体莫过于铁屑溶解在稀硫酸中时释放出的挥发性气体。这种气体极易燃，因此被称为“可燃气体”（inflammable air）。充满这种气体的气球会高高飘浮在空中。

There was another suffocating gas left behind when a candle was burned in a covered jar. It did not precipitate limewater, and since it was evidently related to combustion was called “phlogisticated” air—or azote, from the Greek word for “lifeless.” Most mysterious of all was a volatile gas emitted when iron filings were dissolved in dilute sulfuric acid. It was so combustible that it was named “inflammable air.” A balloon filled with it would float high above the ground.

问题是，这些新的空气是元素，还是像普里斯特利认为的那样，是“正常”空气的变体，是通过添加或减少燃素产生的。

The question was whether these new airs were elements or, as Priestley believed, modifications of “normal” air, produced by adding or subtracting phlogiston.

拉瓦锡小心翼翼地抑制住自己的怀疑，重复了同事们的一些工作。他证实，燃烧磷制磷酸或硫制硫酸确实会使物质变重——这与煅烧金属的现象相同。但究竟是什么导致了这种变化呢？他认为自己找到了答案。他用燃烧器加热密封在烧瓶中的锡，发现整个装置加热前后重量相同。他慢慢打开烧瓶，听到空气呼啸而入，这时重量才开始增加。也许物质燃烧并非因为释放燃素，而是因为它们吸收了某种空气。

Carefully keeping his skepticism in check, Lavoisier repeated some of his colleagues’ work. He confirmed that burning phosphorus to make phosphoric acid or sulfur to make sulfuric acid indeed left the substances heavier—the same thing that happened when you calcined metals. But what was causing the change? He thought he knew the answer. Using a burning glass to heat tin that had been sealed inside a flask, he found that the entire apparatus weighed the same before and after. Slowly opening the vessel he heard air whistle in, and only then was there a gain in weight. Maybe things burned not because they emitted phlogiston but because they absorbed some kind of air.

用放大镜在罐子里燃烧密当粉。玛丽·安妮·拉瓦锡绘图。

Burning litharge in a jar with a magnifying glass. Drawing by Marie Anne Lavoisier

如果真是如此，那么还原物质——将矿石冶炼回纯金属——应该能将空气排出。他称取了一块名为密铁矿的铅锭，将其与一块木炭一起放在一个盛有水的容器中。然后，他将一个钟罩倒扣在上面。用放大镜加热铅锭，他从水的位移中观察到有气体逸出。小心地将其从钟罩中取出后，他发现它能熄灭火焰并析出石灰水。看来固定的空气是还原反应的产物，但事情是否还有更深层次的原因呢？

If so, then reducing a substance—smelting an ore back into a pure metal—should force the air back out again. He measured out a calx of lead called litharge and placed it, along with a piece of charcoal, on an island pedestal in a basin of water. Then he inverted a bell jar on top. Heating the calx with a magnifying glass, he could see from the displacement of the water that a gas was coming out. Carefully withdrawing it from the jar, he found that it extinguished flames and precipitated limewater. Fixed air appeared to be a product of reduction, but was there more to the story than that?

答案最终揭晓，它是一种名为“煅烧汞”（mercurius calcinatus）的红色物质，巴黎的药剂师将其作为治疗梅毒的药物出售。每盎司的价格高达18里弗尔甚至更高——相当于今天的1000美元左右——因此，研究煅烧汞几乎和燃烧钻石一样奢侈。与其他的氧化汞一样，煅烧汞可以通过在烈火上加热纯金属制成。但出乎意料的是，当继续加热时，它会变回水银。换句话说，煅烧汞无需木炭即可还原。那么，燃素又来自哪里呢？1774年，拉瓦锡和法国科学院的一些同事证实，煅烧汞确实可以在“不添加任何物质”的情况下被还原，重量减少约十二分之一。

The answer turned out to lie in a reddish substance called mercurius calcinatus, or calx of mercury, sold by Parisian apothecaries as a treatment for syphilis. With a price of eighteen livres and up per ounce—about $1,000 in today’s currency—experimenting with mercurius calcinatus was almost as extravagant as burning diamonds. Like all calxes, it could be produced by heating the pure metal over an intense flame. But when heated further it changed, against all expectations, back into quicksilver. In other words, mercurius calcinatus could be reduced without the presence of charcoal. But what then was supplying the phlogiston? In 1774, Lavoisier and some colleagues from the French Academy confirmed that calx of mercury could indeed be reduced “without addition,” losing about one-twelfth of its weight.

普里斯特利也在研究这种物质，他用放大镜加热它，并收集产生的气体。“令我惊讶不已的是，”他后来回忆道，“蜡烛在这种气体中燃烧得异常旺盛……我完全无法解释这种现象。”他发现实验鼠在这种气体中生长良好后，便亲自尝试吸入。“我感觉之后一段时间，我的胸口格外轻松。谁知道呢，也许过不了多久，这种纯净的空气就会成为一种时髦的奢侈品。到目前为止，只有两只实验鼠和我才有幸吸入过它。”

Priestley was also experimenting with the stuff, heating it with a magnifying glass and collecting the fumes. “What surprised me more than I can well express,” he would later report, “was that a candle burned in this air with a remarkably vigorous flame…. I was utterly at a loss how to account for it.” After finding that a laboratory mouse thrived on the gas, he tried breathing it himself. “I fancied that my breast felt peculiarly light and easy for some time afterwards. Who can tell but that, in time, this pure air may become a fashionable article in luxury. Hitherto, only two mice and myself have had the privilege of breathing it.”

燃烧和呼吸之火得以旺盛的气体必然是燃素的极佳吸收剂，因此普里斯特利将其命名为“脱燃素空气”——最纯净的空气。并非只有他一人持此观点。在瑞典，一位名叫卡尔·威廉·舍勒的药剂师正在研究他称之为“火之空气”的物质的特性。

A gas in which the fires of combustion and respiration flourished must be a particularly good absorber of phlogiston, so Priestley named it “dephlogisticated air”—air in its very purest form. He was not the only one thinking along this line. In Sweden, an apothecary named Carl Wilhelm Scheele was studying the properties of what he referred to as “fire air.”

此时，拉瓦锡称还原煅烧汞（mercurius calcinatus）所释放的气体为“极易呼吸”或“生命之气”，并且像普里斯特利一样，他认为这就是纯净的普通空气。但他遇到了一个难题。当他尝试用木炭还原煅烧汞（mercury calcinatus）——这是传统的还原方法——时，释放出的气体与他从铅丹（litharge）中得到的气体相同：这种气体能熄灭蜡烛并沉淀石灰水。为什么不用木炭还原煅烧汞会产生生命之气，而用木炭还原却会产生令人窒息的固定气体呢？

By now Lavoisier was calling the gas expelled by reducing mercurius calcinatus “eminently breathable” or “vital” air, and like Priestley he thought it was ordinary air in its pristine form. But he had run across a complication. When he tried reducing mercury calx with charcoal—the old-fashioned way—it released the same gas he had obtained from litharge: one that extinguished candles and precipitated limewater. Why would reducing mercury calx without charcoal produce vital air while reducing it with charcoal produced suffocating fixed air?

只有一个办法可以弄清楚。他从架子上拿出一个叫做“垫形瓶”的烧瓶，瓶底是圆的，瓶颈细长。他把烧瓶加热，然后弯曲瓶身，使其先向下弯曲，再向上弯曲。

There was one way to find out. He took from his shelves a flask called a matrass, round on the bottom with a long skinny neck, which he heated and bent so that it curved down and then up again.

如果说他1769年实验中的烧瓶像鹈鹕，那么这个烧瓶看起来更像火烈鸟。他将四盎司纯汞倒入圆底烧瓶（图中的A）中，然后将其放在炉子上，瓶颈向下伸入一个同样装满汞的敞口槽中，再向上伸入一个钟罩中。这个钟罩将作为测量实验过程中空气消耗量的装置。用纸质标签标记液位（LL）后，他点燃炉子，将A室中的液态汞加热至接近沸腾。

If the flask in his experiment of 1769 resembled a pelican, this one looked more like a flamingo. He poured four ounces of pure mercury into the round bottom chamber (A on the diagram) and set it on a furnace with the neck dipping down into an open trough, also filled with mercury, and then up into a bell jar. This would serve as a gauge to measure how much air was consumed during the experiment. After marking the level (L L) with a paper label, he lit the furnace and brought the liquid metal in chamber A almost to a boil.

在“火烈鸟烧瓶”中加热水银。插图由玛丽·安妮·拉瓦锡绘制。

Heating mercury in a “flamingo flask.” Drawing by Marie Anne Lavoisier

第一天几乎什么也没发生。少量水银蒸发后沿着垫壁凝结，聚集成足够重的液滴，滑落回底部。但到了第二天，水银表面开始出现细小的红色斑点——这是水银沉淀。接下来的几天里，这层红色的沉淀物不断增大，直到无法继续生长。第十二天，拉瓦锡停止了实验并进行了一些测量。

On the first day nothing much happened. Small amounts of quicksilver evaporated and condensed along the wall of the matrass, combining into blobs heavy enough to slide back down to the bottom. But on the second day tiny red spots started to appear on the surface of the mercury—the calx. For the next few days the reddish crust increased in size until it could grow no larger. On the twelfth day Lavoisier stopped the experiment and took some measurements.

此时，钟罩内的水银柱已经上升到刻度线以上，排开了一部分被氧化钙吸收的空气。拉瓦锡根据实验室内的温度和压力变化进行校正后计算得出，空气的体积减少了约六分之一，从50立方英寸减少到42到43立方英寸之间。空气的性质也发生了变化。当一只老鼠被放入装有剩余空气的容器中时，它挣扎着呼吸，“当蜡烛插入其中时，它就像浸入水中一样熄灭了。”但由于这种气体没有析出石灰水，因此它一定是氮而不是固定气。

By now the mercury in the bell jar had risen above the mark, displacing some of the air that had been absorbed by the calx. Adjusting for temperature and pressure changes in the lab, Lavoisier calculated that the air had been depleted by about one-sixth of its volume, from fifty cubic inches to between forty-two and forty-three. It had also changed in nature. When a mouse was put inside a container of this leftover air, it struggled for breath, and “when a taper was plunged into it, it was extinguished as if it had been immersed into water.” But since the gas did not precipitate limewater it had to be azote rather than fixed air.

但燃烧的汞究竟从空气中吸收了什么呢？拉瓦锡撇去金属表面形成的红色结壳，将其放入蒸馏釜中加热，直至其重新变成纯净的水银，并释放出七八立方英寸的气体——这与煅烧过程中吸收的气体量大致相同。在这种气体的作用下，蜡烛燃烧时“光芒四射”，而木炭燃烧时，非但没有闷烧，反而“发出耀眼的光芒，令人目眩”。

But what had the burning mercury taken from the air? Skimming off the red crust that had formed on the metal, Lavoisier heated it in a retort until it turned back into pure quicksilver, emitting seven or eight cubic inches of gas—approximately the same amount that had been absorbed during calcination. Exposed to this gas a taper burned “with a dazzling splendor” and charcoal, rather than smoldering, “threw out such a brilliant light that the eyes could hardly endure it.”

这是一个关键时刻。燃烧的汞吸收了大气中的重要空气，留下了氮元素。还原汞则再次释放了重要的空气。他成功地将大气的两大主要成分分离了出来。

It was a pivotal moment. Burning mercury absorbed vital air from the atmosphere, leaving behind azote. Reducing mercury released the vital air again. He had separated the two main components of the atmosphere.

在实验的最后，他将八份自己的生命之气与四十二份氮元素重新混合，并证明它具有普通空气的特性。分析与综合：“这是化学中能够获得的最完整的证明，即空气的分解及其重组。”

In a denouement he recombined eight parts of his vital air with forty-two parts of the azote and showed that it had the characteristics of ordinary air. Analysis and synthesis: “Here is the most complete kind of proof that can be attained in chemistry, the decomposition of air followed by its recomposition.”

拉瓦锡于1777年向科学院宣读了研究结果。当时并不存在燃素。燃烧和煅烧是由于物质吸收了空气——他称之为氧气，因为氧气在酸的形成过程中起着重要作用。（希腊语中“氧”意为“尖锐的”。）当空气中的氧气被燃烧消耗殆尽后，剩下的不可呼吸的氮就是氮气。

Lavoisier read the results to the Academy of Science in 1777. There was no phlogiston. Burning and calcination were caused when a substance took in vital air—oxygen he would call it because of its role in the formation of acids. (Oxy in Greek means sharp.) When the oxygen is depleted from the air by burning, the unbreathable azote left behind is nitrogen.

至于人们一直称之为固定空气的气体，它是还原过程中释放的氧气与木炭中的某些物质结合而产生的，从而产生了我们现在所说的二氧化碳。

As for the gas that people had been calling fixed air, it was produced when the oxygen emitted during reduction combined with something in the charcoal, producing what we now call carbon dioxide.

多年来，拉瓦锡的同事们，尤其是普里斯特利，一直抱怨他窃取了他们的劳动成果。普里斯特利曾与拉瓦锡一家共进晚餐，向他们讲述了他研究的“脱燃素空气”，瑞典药剂师舍勒也曾写信给拉瓦锡，描述了他的研究。然而，他们始终认为氧气就是不含燃素的空气。

FOR YEARS Lavoisier’s colleagues, particularly Priestley, grumbled that he had grabbed credit for work they had also done. Priestley had dined with the Lavoisiers, telling them about his dephlogisticated air, and Scheele, the Swedish apothecary, had sent Lavoisier a letter describing his work. But all the while they continued to think of oxygen as air devoid of phlogiston.

在他们2001年首演的戏剧《氧气》中，两位化学家卡尔·杰拉西和罗尔德·霍夫曼设想了三位科学家被瑞典国王召集到斯德哥尔摩，以决定谁才是真正的氧气发现者。舍勒是第一个提取出氧气的人，普里斯特利是第一个发表氧气存在消息的人，但只有拉瓦锡真正理解了他所发现的氧气究竟是什么。

In their play Oxygen, which premiered in 2001, two chemists, Carl Djerassi and Roald Hoffmann, imagine the three scientists summoned to Stockholm by the king of Sweden to decide who should be revered as the true discoverer. Scheele was the first to extract the gas and Priestley the first to publish word of its existence, but only Lavoisier understood what he had found.

他还洞察到了更深层次的东西：质量守恒定律。在化学反应中，物质——燃烧的汞，变化的空气——会改变形态。但质量既不会被创造，也不会被消灭。投入的物质必须以相同的量返回。正如税务员所说，账目必须平衡。

He had also seen through to something deeper: the law of conservation of mass. In a chemical reaction, matter—the burning mercury, the altered air—changes form. But mass is neither created nor destroyed. The same amount going into the transaction must come out the other end. The ledgers must balance, a tax collector would say.

1794年，在恐怖统治时期，拉瓦锡和玛丽·安妮的父亲与其他包税人一起被判为国家敌人，并被用马车押送到革命广场。广场上搭建了一个木制平台，其气势与拉瓦锡曾经焚烧钻石的平台不相上下。然而，取代巨型透镜的却是另一项法国科技的象征——断头台。

In 1794, during the Reign of Terror, Lavoisier and Marie Anne’s father were convicted along with other tax farmers as enemies of the state and brought by wagon to the Place de la Révolution, where a wooden platform had been erected, every bit as imposing as the one on which Lavoisier had once burned diamonds. In place of the giant lenses was another example of French technology, the guillotine.

前段时间，网上流传着一个故事，说拉瓦锡在被处决前安排了一项最后的实验。断头台在法国被宣传为一种特别人道的死刑方式，可以瞬间无痛地杀死犯人。这或许是一个验证其人道性的机会。拉瓦锡说，当他感觉到刀刃触碰到脖子的那一刻，他就开始尽可能多地眨眼。一个站在人群中的助手会帮他数眨眼的次数。这个故事很可能是假的，但听起来确实很像拉瓦锡会做的事。

A story ricocheting through the Internet a while ago insisted that before his execution Lavoisier arranged to perform one final experiment. The guillotine had been promoted in France as a particularly humane form of execution, manufacturing instantaneous and painless death. Here was a chance to find out. The moment he felt the blade touch his neck Lavoisier would begin blinking his eyes as many times as he could. An assistant standing in the crowd would count the blinks. The story is probably not true. But it sounds like just the kind of thing Lavoisier might have done.

第五章

CHAPTER 5

路易吉·伽伐尼

Luigi Galvani

动物电

Animal Electricity

路易吉·伽伐尼

Luigi Galvani

因为在实验中很容易受到欺骗，并认为自己已经看到和发现了我们想要看到和发现的东西。

For it is easy in experimentation to be deceived, and to think one has seen and discovered what we desire to see and discover.

——路易吉·伽伐尼

—Luigi Galvani

十八世纪中期，正值电学风靡一时之际，一位业余科学家站在伦敦皇家学会的讲台上，描述了后来被称为“西默定律”的现象：异色袜子相互吸引，同色袜子相互排斥。这位名叫罗伯特·西默的政府职员，为了在冬天保持双脚舒适，习惯穿两层袜子。早上，他会在黑色羊毛袜外面套上一层白色丝袜；下午，他会把两层袜子反过来穿。在换袜子的过程中，两种不同材质的袜子会发出噼啪声，并冒出相反的电荷。西默，这位后来被称为“赤脚哲学家”的人，会靠在椅背上，惊叹于这种奇妙的现象。

MIDWAY through the eighteenth century, when electricity was all the rage, an amateur scientist stood before the Royal Society in London and described what might be called Symmer’s law: opposite-colored socks attract while like-colored socks repel. To keep his feet comfortable in winter, the speaker, a government clerk named Robert Symmer, was accustomed to wearing two layers of stockings. In the morning he would pull white silk socks over a black woolen pair. In the afternoon he would reverse them. During the transition, the two different materials crackled and bristled with opposite charges, and Symmer, who became known as the barefoot philosopher, would sit back in his chair marveling at the results.

“当用一只手拿着两只黑袜子，另一只手拿着两只白袜子进行这项实验时，”他报告说，“就会出现一种非常奇特的景象：相同颜色的袜子相互排斥，不同颜色的袜子相互吸引，使它们变得躁动不安，这着实令人愉悦。”

“When this experiment is performed with two black stockings in one hand, and two white in the other,” he reported, “it exhibits a very curious spectacle: The repulsion of those of the same colour, and the attraction of those of different colours, throws them into an agitation that is not unentertaining.”

这是电学研究浪漫主义时代的鼎盛时期，科学家们争论着电究竟是蒸汽、液体，还是如本杰明·富兰克林推测的那样，是“微妙的粒子”。科学家们（他们被称为“电工”）转动着静电发生器的齿轮——巨大的旋转圆盘和球体，通过摩擦产生电荷——让冲击波沿着人链传递。用丝绳将一个人吊在椅子上（防止他接地），他的头就能像圣像周围的金箔光环一样闪闪发光。一位从观众席中挑选出来的年轻女子，被赋予电荷后，会用一个令人难忘的吻让她的追求者“触电”。正极与负极相遇。

This was the height of the romantic era in electrical research, with scientists debating whether electricity was a vapor, a fluid, or, as Benjamin Franklin speculated, “subtle particles.” Cranking the wheels of their static-electricity generators—great spinning disks and globes that were rubbed to produce a charge—scientist-entertainers (they were called “electricians”) sent shock waves traveling hand by hand through human chains. Suspend a man in a chair with silk ropes (to keep him from being grounded) and his head could be made to glow like the gold leaf aura around the image of a saint. A young woman, picked from the audience and given a charge, would electrify her suitor with an unforgettable kiss. Positive, meet negative.

尽管电能看似虚幻，但它却真实存在，甚至可以储存在一个罐子里。罐子内外都包裹着两片分别连接到摩擦发电机正负极的锡箔纸，罐子便会带上电荷——玻璃一侧带负电，另一侧带正电——即使移除导线后，电荷仍然会残留很长时间。触摸这个被称为莱顿瓶的原始电容器的两侧，就像被鳗鱼蜇了一下一样。

Ghostly as it seemed, electricity was tangible enough to store in a jar. Wrapped inside and out with two pieces of foil connected to opposite poles of a friction generator, the vessel took on a charge—negative on one side of the glass and positive on the other—that lingered long after the wires were removed. Touching both sides of this primitive capacitor, called a Leyden jar, was like being stung by an eel.

西默的袜子。出自法国神父兼物理学家让-安托万·诺莱的论文。

Symmer’s socks. From a treatise by Jean-Antoine Nollet, a French abbé and physicist

科学家们对闪电能使残疾人行走或使植物快速生长的报道进行了深入探讨，经验事实与幻想交织在一起。约瑟夫·普里斯特利推测，电是由大脑中的燃素转化而来，并进一步提出，电是肌肉运动的根源……也是鹦鹉羽毛闪烁的虹彩、某些动物在夜间捕猎时“据说会发出的光芒”以及“某些特定性情的人，尤其是在某些特殊情况下”发出光芒的原因。

Empirical fact tangled with fantasy as scientists deliberated over reports of lightning spontaneously causing cripples to walk or plants to grow faster. Speculating that electricity was produced in the brain—from the conversion of phlogiston—Joseph Priestley went on to propose that it was responsible for muscular motion…as well as for the iridescent sheen of parakeet feathers and the light “said to proceed from some animals” when they stalked their prey at night, and even from people “of a particular temperament, and especially on some extraordinary occasions.”

一台十八世纪的静电发生器和本杰明·富兰克林绘制的两个莱顿瓶的示意图

An eighteenth-century static electricity machine and Benjamin Franklin’s drawing of two Leyden jars

另一些人则认为，摩擦会在体内产生某种“神经电”液体。这真是一个惊人的想法。就像西默的袜子一样，神经和骨骼会与肌肉摩擦，从而产生生命力——电。

Others thought some kind of “nerveo-electrical” fluid was produced in the body by friction. It was a startling idea. Like Symmer’s socks, nerves and bones would rub against muscles, generating the life force, electricity.

1786 年 4 月的一个傍晚，在 Symmer 发现脊髓之后超过四分之一世纪，中年解剖学教授 Luigi Galvani 带着一卷金属丝和一只青蛙的腿，走到他位于博洛尼亚家附近的赞博尼宫的露台上。正如他经常说的那样，这只青蛙的腿是“按常规方式”处理的：脊髓被切断，坐骨神经（或小腿神经）垂了出来。

ON AN April evening in 1786, more than a quarter century after Symmer’s discovery, Luigi Galvani, a middle-aged professor of anatomy, walked to a terrace at the Palazzo Zamboni near his home in Bologna, carrying a roll of metal wire and the legs of a frog prepared, as he often put it, “in the usual manner”: severed at the spinal cord with the sciatic (or crural) nerves dangling out.

南方乌云密布，他把那只无头的标本放在桌子上，用一根事先架在头顶的铁丝绳把它拴住。然后他等待着雷雨的到来，观察到标本的腿会在闪电划过时抽搐，仿佛在预示着即将到来的雷声。

As clouds gathered to the south, he positioned the headless specimen on a table and connected it to a clothesline of wire, which he had strung overhead. Then he waited for an electrical storm, observing that the legs twitched in response to lightning as though warning of the coming thunder.

闪电引起的肌肉收缩。摘自伽伐尼《论电在肌肉运动中的作用》

Muscular contractions caused by lightning. From Galvani’s De Viribus Electricitatis in Motu Musculari Commentarius

多年来，伽伐尼在他的实验室里通过发电机产生的电流或莱顿瓶释放的电流刺激青蛙神经，从而获得了类似的效果。赞博尼宫上方的演示证实了“天然”电流与“人工”电流产生的生理反应相同。无论采用何种方式，它都能使肌肉运动。

Over the years Galvani had produced similar effects in his laboratory, stimulating frog nerves with electricity cranked from a generator or discharged from a Leyden jar. The demonstration above the Palazzo Zamboni confirmed for him that “natural” electricity produced the same physiological reaction as “artificial” electricity. One way or another, it made muscles move.

然而，有一个实验让他难以解释。几年前，他的一位助手不小心用手术刀碰到了青蛙裸露的神经，与此同时，另一位助手在附近操作发电机时产生了一个小火花。虽然机器和被解剖的动物之间没有连接任何电线，但它的腿却剧烈地抽搐起来，如同癫痫发作一般。从那时起，伽伐尼就一直在研究这种现象。

There was one experiment, however, that he was finding harder to interpret. Several years earlier one of his assistants had happened to touch a scalpel to a frog’s exposed nerve just as a second assistant, working nearby with a generator, created a small spark. No wires ran from the machine to the dissected animal, but its legs contracted violently, as if in a seizure. Galvani had been investigating the phenomenon ever since.

他很快便确定这种反应并非手术刀刺激所致。确认发电机处于空转状态后，他用金属刀片按压神经。无论他如何用力按压，肌肉都纹丝不动。这种反应显然是电刺激引起的。

Early on he established that the response wasn’t caused simply by irritation from the scalpel. Making sure the generator was idle, he pressed against the nerve with a metal blade. No matter how insistently he probed, the muscles lay motionless. The effect clearly appeared to be electrical.

静电和青蛙腿

Static electricity and frogs’ legs

其他实验表明，铁制圆筒可以拾取火花并使腿部抽搐，但玻璃棒则不行。然而，有时即使是金属手术刀也无法引起反应。伽伐尼很快意识到，当他握住手术刀的骨柄而没有触碰铆钉或刀刃时，就会出现这些失败的情况。实验者自身似乎也参与了反应。为了验证这一假设，他将金属圆筒单独放在桌子上，使其接触到神经，然后转动发电机。结果腿部纹丝不动。

Other experiments showed that an iron cylinder would pick up the spark and make the legs twitch, but not a glass rod. Sometimes, however, even a metal scalpel failed to provoke a response. Galvani quickly realized that these failures occurred when he held the instrument by its bone handle without touching the rivets or the blade. Somehow the experimenter himself seemed to be part of the reaction. To test this hypothesis, he placed the metal cylinder by itself on the table so that it touched the nerve, and then cranked the generator. The leg lay still.

他一步步排除各种变量。如果他把神经连接到一根长金属线而不是短圆柱体上，远处的火花确实会让青蛙的腿跳动起来。情况逐渐明朗起来。科学家们早已知道，电可以远距离影响人类：当闪电击中附近时，人脖子上的汗毛会竖起来。启动发电机后，空气中会产生一种紧张感——一种“带电氛围”。手术刀的握柄和手术刀本身就像一根天线——避雷针——通过青蛙释放电流。

Step by step, he eliminated the variables. If he connected the nerve to a long metal wire instead of a short cylinder, a distant spark did make the legs jump. The situation was becoming a bit clearer. Scientists already knew that electricity could exert its influence across a distance: the hairs on a human neck bristled when a lightning bolt struck nearby. Cranking the generator caused a tension to build in the air—an “electrical atmosphere.” The holder of the scalpel and the scalpel itself served as a kind of antenna—a lightning rod—discharging itself through the frog.

但伽伐尼怀疑，或许还有更奇怪的事情正在发生。如果青蛙仅仅是对空气中传输的人造电流做出反应，那么抽搐的强度应该取决于火花的距离。他将一个金属钩连接到青蛙的脊髓上，钩子再连接到一段导线上，然后在不同的距离重复实验，最远将青蛙放在距离发电机150英尺（约45米）的地方。青蛙的反应依然强烈——即使将青蛙的腿放在锡制圆筒内或真空室中隔离。一次又一次的实验结果似乎都指向了伽伐尼凭直觉得出的结论：机器产生的电流并非青蛙跳跃的主要原因。它只不过是一个触发器，激发了自然存在的、流经神经的“动物电”。

But maybe, Galvani suspected, something even stranger was happening. If the frog was merely reacting to artificial electricity transmitted through the air, the intensity of the twitching should depend on the proximity of the spark. Attaching a metal hook to a frog’s spinal cord and the hook to a length of wire, he repeated the experiment at various distances, placing the frog as far as 150 feet away from the generator. The reaction was as vigorous as ever—even when the legs were shielded inside a tin cylinder or isolated in a vacuum chamber. One variation after another seemed to point to what Galvani had instinctively come to believe: that the electricity produced by the machine was not the primary cause of the jumping. It was no more than a trigger, exciting a naturally occurring “animal electricity” that flowed through the nerves.

伽伐尼深知实验者很容易自欺欺人，只看到自己想看到的。他谨慎地观察着他的“猎物”。九月初，也就是赞博尼宫实验几个月后，他拿了几只被截肢的青蛙，用金属钩把它们挂在阳台的铁栏杆上。这一次，没有闪电，也没有发电机冒火花，但青蛙的腿还是抽搐了一下。

Galvani knew how easy it was for an experimenter to fool himself, to see what he wanted to see. Warily he circled his prey. Early in September, several months after the experiment at the Palazzo Zamboni, he took several of his truncated frogs and hung them by metal hooks from an iron railing on his balcony. This time there was no lightning, no generators sparking, and yet the legs twitched anyway.

他推断，电流不可能源自金属内部。单个导体——钩子和铁轨——无法储存电荷。要产生电势，正负极必须像莱顿瓶那样严格分开。更难排除的另一种可能性是，大气中的电荷不知何故“渗入动物体内并积聚”，然后在钩子接触铁轨时释放出来。那天天空晴朗，但伽伐尼还是想排除这种可能性。

The electricity could not be originating inside the metal, he reasoned. A single conductor—the hook and rail—cannot hold a charge. To create a potential, negative and positive must be kept carefully apart, as in a Leyden jar. Harder to discount was the possibility that atmospheric electricity had somehow “crept into the animal and accumulated,” rushing out when the hook made contact with the rail. The sky that day was clear, but Galvani wanted to rule out the possibility.

他一手抓起一只青蛙，用它身上植入的钩子把它吊起来，让青蛙的脚尖触碰到一个银盒子的顶部。另一只手拿着一块金属片，轻轻触碰盒子的光滑表面，形成回路，青蛙便跳了起来。他又抓住青蛙的躯干，让钩子和一只脚同时擦过扁平的导体，同样的事情也发生了：“就在脚触碰到表面的那一刻，腿部肌肉全部收缩，抬起了腿。”脚落回表面后，肌肉再次收缩……如此反复，青蛙不停地跳啊跳，直到筋疲力尽。这难道不是动物电吗？

With one hand he picked up a frog, dangling it by its implanted hook so that the feet touched the top of a silver box. Holding a piece of metal in his other hand, he touched it to the same shiny surface, completing a circuit and causing the frog to jump. The same thing happened when he held the frog by the torso so that both the hook and one of the feet brushed against the flat conductor: “At the very moment the foot touched the surface, all the leg muscles contracted, lifting the leg.” When the foot fell back to the surface, it contracted again…and again, the frog hopping and hopping until its energy was spent. What could this be but animal electricity?

1791年，伽伐尼发表了题为《论电对肌肉运动的影响》（De Viribus Electricitatis in Motu Musculari Commentarius）的研究成果，提出青蛙的肌肉就像一个莱顿瓶，能够储存和释放某种有机电。在仔细描述实验并分析结果后，他开始进行推测。他认为，在人体内，过量的电可能会导致烦躁不安、面色潮红，极端情况下甚至会引发癫痫发作。他还短暂地涉足了自己专业领域之外的领域，提出闪电和地震可能存在某种关联：“但推测也应有所限度！”他希望将来能够研究电是否参与了人体的各种功能：“关于血液循环和体液分泌，这些内容我们将在另一部评注中尽快发表，等我们有更多空闲时间的时候。”

In 1791, Galvani published his findings as De Viribus Electricitatis in Motu Musculari Commentarius (Commentary on the Effect of Electricity on Muscular Motion), proposing that the frog’s muscle was like a Leyden jar, storing and discharging some kind of organic electricity. After carefully describing his experiments and analyzing the results, he allowed himself to speculate. In people, he proposed, an excess of electricity might cause fidgeting, flushing, or in extreme situations epileptic seizures. Venturing briefly outside his own area of expertise, he suggested that lightning and earthquakes might somehow be related: “But let there be a limit to conjectures!” In time he hoped to investigate whether electricity was involved in all manner of bodily functions: “on circulation of the blood and secretion of the humors, these things we will publish as soon as possible in another commentary, when we have found a little more leisure.”

起初，欧洲最伟大的电学家之一亚历山德罗·伏特对伽伐尼的发现印象深刻，宣称这些实验将动物电列为“已证实的真理之一”。然后，他礼貌地逐条驳斥了这一理论。

AT FIRST Alessandro Volta, one of Europe’s greatest electricians, was impressed by Galvani’s discovery, declaring that the experiments had placed animal electricity “among the demonstrated truths.” Then he politely proceeded to dismantle the theory piece by piece.

他以一只完整的青蛙为实验对象，尝试用金属条触碰青蛙的背部，用硬币或钥匙触碰青蛙的腿。然后，他将两个探针的顶端合拢，形成一个弧形。结果与伽伐尼所描述的“抽搐、痉挛和抖动”相同——但前提是他必须使用两种不同的金属。

Taking as his subject an entire frog, he tried touching its back with a strip of metal and its leg with a coin or a key. Then he closed the arc by bringing the tops of the two probes together. The result was “the same convulsions, spasms and jerks” that Galvani had reported—but only if he used two different kinds of metals.

伽伐尼曾在自己的实验中报告说，“双金属弧”似乎会放大收缩，但他认为这不过是个无关紧要的细节。起初，伏特也持类似观点，他认为金属的组合以某种方式促进了青蛙自身电流在闭合电路中的流动。但后来他进行了更深入的观察。

Galvani had reported in his own experiments that a “bimetallic arc” seemed to amplify the contractions, but he considered this no more than a diverting detail. At first Volta was similarly inclined, proposing that the combination of metals somehow encouraged the flow of the frog’s own electricity as it rushed through the completed circuit. But then he took a closer look.

在暴露出一条坐骨神经后，他用两个微小的金属夹子像项圈一样夹住它，中间留有一条细小的缝隙。一个夹子是锡制的，另一个是银制的。当他闭合电路——将两个夹子接触在一起或用导线连接它们——青蛙的肢体立刻抽搐起来。他用锡和黄铜也产生了类似的效果。伏特逐渐相信，导电电弧不仅仅是释放甚至加速动物电的静止连接，它才是能量的真正来源。青蛙腿的抽搐就像一台非常灵敏的仪表的指针。它所指示的是一种新发现的现象：双金属电。“伽伐尼的理论和解释……基本上都被否定了，”伏特写信给一位同事说，“整个理论体系都岌岌可危。”

After exposing a sciatic nerve, he attached two tiny metal clips, like collars, leaving a slight gap in between. One clip was tin and the other was silver. The moment he closed the circuit—touching the clips together or bridging them with a wire—the limb convulsed. He produced a similar effect with tin and brass. The conducting arc, Volta was coming to believe, was not just a quiescent connection discharging or even accelerating animal electricity. It was the actual source of the energy. When the frog’s leg twitched, it was acting like the needle of a very sensitive meter. What it was indicating was the presence of a newly discovered phenomenon: bimetallic electricity. “Galvani’s theory and explanations…are largely disqualified,” Volta wrote to a colleague, “and the entire edifice is in danger of collapsing.”

当伽伐尼的青蛙在银盒盖上跳舞时，它只不过是对电击做出了反应。伏特的结论既绅士又残酷：“如果事情真是如此，那么伽伐尼所声称的、并通过他精妙的实验似乎证明的动物电，还剩下什么呢？”

When Galvani’s frog danced on the lid of a silver box, it was merely reacting to electrical shocks. Volta’s conclusion was as gentlemanly as it was cruel: “If that is how things are, what is left of the animal Electricity claimed by Galvani, and seemingly demonstrated by his very fine experiments?”

G·阿尔瓦尼迅速接受了挑战。的确，人们曾用黄铜钩将蛙腿悬挂在铁轨上。但电弧并非一定要由双金属构成：他用铁钩也得到了类似的结果。回到实验室后，他和他的支持者证明，用两块明显相同的金属同时接触肌肉和神经，就能诱发抽搐。

GALVANI was quick to rise to the challenge. It was true that brass hooks had been used to hang frog legs from an iron rail. But the arc did not have to be bimetallic: he reported similar results with iron hooks. Returning to the laboratory, he and his supporters showed that they could elicit convulsions by simultaneously touching muscle and nerve with two pieces of metal that were obviously identical.

伏特早已准备好了答案。一块金属看起来可能很均匀，但不可避免地会含有杂质——这些肉眼无法察觉的差异就能产生电流。

Volta was ready with an answer. A piece of metal may seem to be homogeneous, but inevitably there would be impurities—imperceptible differences that would generate electricity.

于是，电弧实验的参与者们回到实验室，设计出巧妙的演示装置。他们用一个装满纯汞的玻璃容器来制造导电电弧，将一块解剖过的肌肉漂浮在水面上，并用一根丝线悬挂着它的脊髓。丝线被慢慢放下，直到脊髓接触到汞——啪的一声——肌肉抽搐了一下。

So the Galvanists went back to the lab, devising ingenious demonstrations in which the conducting arc consisted of a glass vessel filled with unadulterated mercury. A dissected muscle was floated on the surface, with its spinal cord suspended from a silk thread. The thread was lowered so that the nerve touched the mercury, and—zap—the muscle twitched.

伏特坚持认为是杂质造成的。如果肌肉能够运动，那么金属内部必然存在差异——这是一个无法反驳的循环论证。

Impurities, Volta insisted. If the muscle moved there had to be dissimilarities in the metal—a circular argument that was impossible to refute.

他们陷入了僵持。对其中一人来说，青蛙产生的电流流经金属电弧；对另一人来说，金属电弧产生的电流流经青蛙。

They were at a standoff. For one man, the frog generated electricity that flowed through the metallic arc. For the other, the metallic arc generated electricity that flowed through the frog.

伽伐尼学派唯一的办法就是把金属从回路中移除。一位实验者证明，一块碳也能起到同样的作用：“那么，为什么要把那些根本不具备金属特性的物体也能产生的效果归因于金属的不同特性呢？”伏特坚持认为，这个实验什么也证明不了，因为碳毕竟是导体。

THE ONLY recourse for the Galvanists was to get the metal out of the loop. One experimenter showed that a piece of carbon served just as well: “Why then ascribe to the different power of metals, effects which can be produced by bodies which certainly have nothing of the metallic quality?” Volta insisted that the experiment proved nothing since carbon was, after all, a conductor.

另一位实验者证明，他只需用一只手触摸青蛙的肌肉，另一只手触摸青蛙被切断的神经，就能产生电流反应。“每次我触摸它，青蛙都会抽搐、跳跃，我甚至想说，它都想从我手中逃脱。”结论似乎显而易见：“金属并非电流的源泉……它们拥有某种神秘的、神奇的力量。”

Another experimenter showed that he could produce the galvanic response simply by touching the frog’s muscle with one of his hands and the animal’s severed nerve with the other. “Each time I touch it, the frog jerks, leaps, and, I’m tempted to say, escapes me.” The conclusion seemed obvious: “metals are not the motors of electricity…. They possess nosecret, magic virtue.”

在迄今为止最具说服力的实验中，伽伐尼完全摒弃了外部导体，他轻轻地摆弄一只解剖过的青蛙，使悬垂的坐骨神经直接接触到控制腿部的肌肉。青蛙立刻踢了一脚。电流除了来自动物自身还能从哪里来呢？

In what seemed the most persuasive experiment yet, Galvani eliminated external conductors entirely, gently manipulating a dissected frog so that the dangling sciatic nerve came directly into contact with the muscle controlling the leg. It immediately gave a kick. Where did the electricity come from but the animal itself?

自信的伽伐尼用伏特自己的话嘲讽他：“但是，如果事情真是如此——如果这种电确实完全是动物特有的，而不是普遍存在的、外在的——那么伏特先生的观点将会如何呢？”

A confident Galvani mocked Volta with his own words: “But if that is how things are—if such electricity is indeed wholly specific to the animal, and not common and extrinsic—what will become of the opinion of Signor Volta?”

它必须进行修改。此时，伏特开始认为肌肉、神经、实验者的双手，甚至青蛙本身都是弱导体，属于“二等”导体。无论是神经接触肌肉，还是银接触黄铜，效果都一样：不同的导体之间会产生他现在称之为接触电的现象。

It simply had to be modified. By now Volta was coming to think of the muscle, the nerve, the experimenter’s hands, and even the frog itself as weak “second-class” conductors. Whether nerve was touched to muscle or silver to brass, the effect was the same: dissimilar conductors produced what he now was calling contact electricity.

伽伐尼在没有外部导体的情况下进行的实验

Galvani’s experiment without external conductors

在伽伐尼早期的实验中，他将两根一级导体——金属手术刀、黄铜钩、银盒盖——用一根潮湿的二级导体（青蛙）隔开。他完全可以用湿纸板，或者像伏特后来证明的那样，用人的舌头。在上面放一枚银币，在下面放一枚铜币，你就能尝到电的味道。涉及单一金属的实验也同样容易解释。一根一级导体在两根二级导体（神经和肌肉）之间形成电弧。最后，你甚至可以完全用柔软的二级导体（手和青蛙）来制造电弧。有机物还是无机物——只要存在差异，就无关紧要。

In Galvani’s earlier experiments a pair of first-class conductors—metal scalpels, brass hooks, silver box lids—were separated by a moist second-class conductor, the frog. He might just as well have used wet cardboard or, as Volta went on to show, a human tongue. Put a silver coin on top and a copper one on the bottom and you could taste electricity. The experiments involving a single metal were as readily explained. One first-class conductor formed an arc between two second-class conductors: the nerve and the muscle. Finally you could make an arc entirely from mushy second-class conductors: a hand and a frog. Organic or inorganic—it didn’t matter, as long as the dissimilarity was there.

现在我们知道，他们两人都是对的。他们各自用一个精妙的实验证明了这一点。

WE KNOW now that both men were right. They each proved it with a beautiful experiment.

首先是伏特。他取了几十个圆盘，一半是铜，一半是锌，将它们一个叠一个地堆叠起来，金属交替，并用浸过盐水的圆形纸板隔开。如果堆叠得足够高，他就能给自己施加轻微的电击。他也可以用银和锡，或者用装有盐水的小杯子代替纸板，用双金属电极将它们串联起来。

First Volta. Taking several dozen disks, half made of copper and half of zinc, he stacked them one on top of another, alternating metals and separating them with round cardboard spacers that had been dipped in salty water. If he made the stack high enough he could give himself a mild shock. He could also use silver and tin, or replace the cardboard with little cups of salt water, chained together with bimetallic electrodes.

他发明了电池。他于1800年发表的论文标题似乎已经说明了一切：《论不同种类导电物质仅接触所激发的电》。伽伐尼的青蛙只不过是伏打电池堆中的一个潮湿隔膜。

He had invented the battery. The title of his paper, published in 1800, seemed to say it all: On the Electricity Excited by the Mere Contact of Conducting Substances of Different Kinds. Galvani’s frog was nothing but a moist separator in a voltaic pile.

伏特的电堆。出自他1800年的手稿

Volta’s electrical pile. From his 1800 manuscript

然而，事实并非如此，伽伐尼的巅峰之作与伏特的实验一样精妙。他“照例”准备了另一只青蛙，让每条腿的主要神经都露在外面。在之前的实验中，他直接用神经接触肌肉。这一次，他用一根细玻璃棒轻轻地将一根神经与另一根神经接触：两个相同的导体，结果却引起了肌肉收缩。如果他只是用玻璃棒刺激第二根神经，则不会出现这种现象。“既然接触仅仅发生在神经之间，那么究竟是什么差异才能解释这种收缩呢？”他问道。他坚持认为，这种效应只能由“动物体内固有的电路”产生。

But no, for Galvani’s crowning experiment was as elegant as Volta’s. He prepared another of his frogs “in the usual manner,” with the primary nerve of each leg sticking out. In the earlier experiment he had touched nerve directly to muscle. This time, using a small glass rod, he nudged one nerve against the other: two identical conductors, and the result was a muscular contraction, one that did not occur if he simply irritated the second nerve with the piece of glass. “Now what dissimilarity could be called in to explain the contractions,” he asked, “since the contact is formed between the nerves alone?” The effect could have been produced, he insisted, only “by a circuit of electricity inherent in the animal.”

尽管两人都未能完全领悟，但他们的实验却相辅相成，因为他们都在围绕着同一个真理打转：自然电、人工电、动物电——电就是电。伏特并没有意识到他用“接触电”观察到的其实是一种化学反应（他甚至认为他的电池是永动机），而伽伐尼则坚持认为生物电本质上有所不同。

Though neither man could quite see it, their experiments complemented each other, for they were dancing around a single truth. Natural, artificial, animal—electricity is electricity. Volta didn’t appreciate that what he was observing with his “contact electricity” was a chemical reaction (he actually thought his battery was a source of perpetual motion), and Galvani clung to the idea that there was something inherently different about biological electricity.

多年以后，生理学家才详细阐述了伽伐尼在伏特的启发下，通过青蛙实验所发现的现象：在生物体内，每个微小的细胞都像一个小型电池，细胞膜如同纸板隔片，带电离子则扮演着锌币和铜币的角色。由此产生的是正负电荷之间的对峙，即我们所说的电压。当肌肉运动或手指触摸石头表面时，电流就会流经神经系统。并不存在虚无缥缈的“生命力”。生命本质上就是电化学反应。

It would be years before physiologists laid out the details of what Galvani, egged on by Volta, had glimpsed with his frogs: how, in an organism, each microscopic cell acts like a little battery, with membranes behaving like cardboard spacers and charged ions playing the role of zinc and copper coins. What results is a standoff between positive and negative, the electromotive force called voltage. When a muscle moves or a finger feels the surface of a stone, a current flows through the nervous system. There is no ethereal “vital force.” Life is electrochemistry.

第六章

CHAPTER 6

迈克尔·法拉第

Michael Faraday

深藏的秘密

Something Deeply Hidden

迈克尔·法拉第

Michael Faraday

我以后每次看到闪电，都会想起他欣赏美丽风暴时的喜悦。他会在窗边站上几个小时，观赏风暴的景象，享受其中；而我们知道，他的脑海中充满了崇高的思考，有时是关于伟大的造物主，有时是关于祂用来治理地球的法则。

I shall never look at the lightning flashes without recalling his delight in a beautiful storm. How he would stand at the window for hours watching the effects and enjoying the scene; while we knew his mind was full of lofty thoughts, sometimes of the great Creator, and sometimes of the laws by which He sees meet to govern the earth.

——玛格丽特·里德，迈克尔·法拉第的侄女

—Margaret Reid, Michael Faraday’s niece

火花。——伏打电池放电产生的耀眼星光，被世人公认为人类通过艺术所能创造的最美丽的光。

Spark.—The brilliant star of light produced by the discharge of a voltaic battery is known to all as the most beautiful light that man can produce by art.

——迈克尔·法拉第，《电学实验研究》

—Michael Faraday, Experimental Researches in Electricity

人人都知道艾达·洛芙莱斯是个麻烦人物。作为诗人拜伦的女儿，她天生桀骜不驯，母亲试图通过让她学习数学来压制这种天性。然而，这种疗法并不完全成功——她曾试图与一位家庭教师私奔。最终她被抓获，驯服后嫁给了一位贵族，但她更喜欢与科学家们为伍。发明家查尔斯·巴贝奇是她的圈子成员之一。他称她为“数字女巫”，而她则自称“科学新娘”。她痴迷于各种新奇的想法：颅相学、催眠术、“神经系统微积分”。1844年，28岁的她与英国最伟大的实验家迈克尔·法拉第开始了暧昧的通信，并提议自己成为他的缪斯和“仙女”。

EVERYBODY knew Ada Lovelace was trouble. The daughter of the poet Byron, she had been born with a wild streak that her mother tried to suppress by occupying the girl’s mind with mathematics. The therapy wasn’t entirely successful—she tried to run off with one of her tutors. She was caught, tamed, and married to a nobleman, but she preferred the company of scientists. The inventor Charles Babbage was part of her coterie. He called her his “Enchantress of Numbers.” She called herself the “Bride of Science.” She was obsessed with new ideas: phrenology, mesmerism, a “calculus of the nervous system.” In 1844, when she was twenty-eight, she struck up a flirtatious correspondence with England’s greatest experimenter, Michael Faraday, proposing that she be his muse and “ladye-fairy.”

我将化身为美丽的幽灵，色彩斑斓，谈吐优雅，只要你一声令下。但现在，我只想做一只安静的小棕鸟，依偎在你身旁，静静地听你教我如何了解你，如何帮助你。我的魔杖任你取用，我把它交到你手中，供你使用。

I will be the beautiful phantom, glowing in colour & eloquence, when you so order me. But I will now be a little quiet brown bird at your side, and gently let you teach me how to know & aid you. But my wand is yours at pleasure, & into your hands I deliver it for your use.

从他谨慎的回答中，很难看出法拉第对她那些热情洋溢、墨迹点缀的赞美之词作何感想。他当时五十三岁，已婚，是一位虔诚的基督徒，正在从如今所谓的精神崩溃中恢复。他大部分的伟大工作——那些将电和磁结合起来的实验——都已完成。或许正是艾达的奉承促使他更进一步，用一个精妙的演示证明了电磁力本身与光有着密切的联系。

It is hard to tell from his careful replies what Faraday thought of her gushings, underscored with stabs of ink. He was fifty-three years old, married, a pious Christian, and in recovery from what would nowadays be called a nervous breakdown. Most of his great work was behind him—the experiments drawing together electricity and magnetism. Maybe it was Ada’s flattery that pushed him to go one step further and show, in an elegant demonstration, that electromagnetism itself is intimately connected with light.

艾达·洛夫莱斯夫人

Lady Ada Lovelace

他们来自截然不同的世界。法拉第的父亲是铁匠，母亲是装订工的学徒，他成功说服了伟大的英国化学家汉弗莱·戴维聘用他担任秘书和助手。起初，他的职责包括担任戴维的贴身男仆，陪同他前往欧洲，并结识了伏特和安德烈-玛丽·安培等名人。后来，法拉第受聘于伦敦皇家学会，开始从事科学领域的日常工作：为韦奇伍德瓷器制造商分析黏土，为东印度公司分析火药，并在威尔士的金属铸造厂研究工业流程。在他与这位年轻的通信对象年龄相仿的时候，一家保险公司曾请他报告鲸油的易燃性，英国海军部则请他报告最佳的肉类干燥方法。大约在1820年末，戴维带着一位丹麦科学家汉斯·克里斯蒂安·奥斯特带来的激动人心的消息来找他。

They had come from different worlds. The son of a blacksmith and a bookbinder’s apprentice, Faraday had persuaded the great English chemist Humphry Davy to take him on as a secretary and assistant. The duties at first included serving as Davy’s valet, traveling with him to Europe, and meeting the likes of Volta and André-Marie Ampère. Hired by the Royal Institution in London, Faraday embarked on a career doing the yeoman’s work of science: analyzing clays for the Wedg-wood china makers and gunpowder for the East India Company, studying industrial processes at metal foundries in Wales. When he was about the age of his young correspondent, an insurance company had asked him to report on the flammability of whale oil, and the British Admiralty on the best ways of drying meat. It was around that time, in late 1820, that Davy came to him with exciting news from a Danish scientist, Hans Christian Oersted.

奥斯特用二十个装满稀酸的容器，并用铜片和锌片串联起来，制成了一个伏打电池。然后，他将装置的一极连接到一根长导线上，并将导线放在指南针上方，与指针平行。当他用导线的另一端接触电池的另一侧时，指南针的指针向西摆动。如果他将导线放在指南针下方，指针则向东摆动。

Oersted had made a voltaic battery by filling twenty vessels with dilute acid and linking them in series with pieces of copper and zinc. Then he connected one pole of the apparatus to a long wire and placed it over a compass, parallel to the needle. The moment he touched the other end of the wire to the opposite side of the battery, the compass needle swung west. If he placed the wire beneath the compass, the needle swung east.

克服了最初的怀疑，戴维和法拉第立即重复了这一演示。与此同时，在巴黎工作的安培证明了平行导线中同向电流会像磁铁一样相互吸引。如果其中一根导线中的电流方向反转，导线就会分开。

Overcoming their disbelief, Davy and Faraday rushed to repeat the demonstration, while Ampère, working in Paris, showed that parallel wires carrying currents in the same direction attracted each other like magnets. If one of the currents was reversed, the wires moved apart.

磁与电之间如此清晰的联系已经足够令人惊讶了。更令人震惊的是，力可以沿圆周运动而不是直线运动。（一位科学家称之为“眩晕电”。）牛顿力学对此毫无预料。法拉第进一步证明，他用一个简陋的装置，包括水银和软木塞，就能使带电导线绕磁铁旋转，或者磁铁绕带电导线旋转。他发明了电动机。如果他将导线弯成环状并连接到电池上，它就变成了一个弱磁铁。如果他将导线缠绕成螺旋状，磁力会更强，集中在线圈的中心。

So clear a connection between magnetism and electricity was surprising enough. What was astonishing was that a force could move in circles instead of straight lines. (“Vertiginous electricity,” one scientist called it.) Nothing in Newtonian mechanics had predicted this. Faraday went on to show that with a crude apparatus using mercury and a cork he could make an electrified wire revolve around a magnet or a magnet around an electrified wire. He had invented the electric motor. If he shaped a wire into a loop and attached it to a battery, it became a weak magnet. If he wound the wire into a spiral, the magnetic force was even stronger, concentrated inside the center of the coil.

奥斯特的实验

Oersted’s experiment

凭借几项巧妙的实验，他跻身欧洲科学界的前沿。之后，他便暂时搁置了科学研究。接下来的十年，他主要从事钢铁和铜的冶金、玻璃制造——这些都是工业时代常见的琐事。在给安培的一封信中，他感叹自己“不幸地将许多时间耗费在了平凡的工作上”，而不是从事自己热爱的研究。他抽出一些时间进行一些更具想象力的活动，比如研究在金属板表面撒上一层薄薄的沙子或粉末，然后用琴弓振动其边缘时出现的波纹状图案，或者说是“波纹”。旁边放置的另一块撒有粉末的金属板也会随之振动。他还研究液体。“在阳光下振动锡板上的水银会产生非常美丽的反射效果，”他描述道，语气颇似牛顿。“在阳光下振动的墨水和水看起来也极其美丽。”直到 1831 年，他才最终重新开始研究线圈和电池。

With a few deft experiments, he had moved to the forefront of European science. And that is where he left things for a while. The next decade was dominated by the metallurgy of steel and copper, the manufacture of glass—more errands of the Industrial Age. In a letter to Ampère, he lamented how many of his days were “unfortunately occupied in very common place employment” instead of the research he loved. He found some time for more imaginative pursuits, studying the undulating patterns, or “crispations,” that appeared when he spread a thin layer of sand or powder across the surface of a metal plate and vibrated its edge with a violin bow. A second plate of powder placed nearby would vibrate in sympathy. He also experimented with liquids. “Mercury on tin plate being vibrated in sunshine gave very beautiful effects of reflection,” he reported, sounding a bit like Newton. “Ink and water vibrated in sunshine looked extremely beautiful.” It was not until 1831 that he finally returned to his coils and batteries.

法拉第的日记中提到，一根导线绕着磁铁旋转。

From Faraday’s diary, a wire rotating around a magnet

那时，英国电工威廉·斯特金已经将裸露的导线缠绕在涂漆的铁芯上，制成了一个足以承受自身重量以上重物的电磁铁。美国人约瑟夫·亨利则使用绝缘导线制造了一个可以承受超过一吨重物的电磁铁。一天夏天，法拉第决定尝试将两个独立的线圈紧密放置在一起。他请皇家研究院的工坊锻造了一个环形铁架，厚度为七分之八英寸，直径为六英寸。他在铁架的一侧缠绕了72英尺长的铜线，并用麻绳和印花布进行绝缘。他称这个线圈为A。在铁架的另一侧，他用大约60英尺长的导线缠绕了B线圈。

By then the English electrician William Sturgeon had wound bare wire around a varnished iron core to make an electromagnet strong enough to hold more than its own weight. Using insulated wire, the American Joseph Henry made an electromagnet that would support more than a ton. One summer day Faraday decided to see what would happen if he put two separate coils in close proximity. He asked the shop at the Royal Institution to forge a ring-shaped iron frame seven-eighths of an inch thick and six inches in diameter. Around one side he wrapped seventy-two feet of copper wire, insulated with twine and calico. This he called coil A. On the other side of the ring, with about sixty feet of wire, he wound coil B.

两个线圈之间并没有直接连接。然而，当他将第一个线圈的导线接触电池的两极时，连接在第二个线圈上的电流计指针开始抖动并振荡，然后才恢复到原来的位置。断开电池后，指针再次移动。或许是想到了他在声学实验中观察到的清脆声响，他设想在初级线圈中产生的“电波”穿过环形线圈，并以某种方式在第二个线圈中产生了电流。他发现了电磁感应，并打开了一扇通往新世界的大门。

There was no direct connection between one coil and the other. Yet when he touched the wires of the first coil to the poles of a battery, a galvanometer attached to the second coil twitched and oscillated before settling back to its original position. Disconnecting the battery made the needle move again. Thinking, perhaps, of the crispations in his acoustic experiments, he envisioned a “wave of electricity” produced in the primary coil traveling through the ring and somehow begetting a current in the second coil. He had discovered electromagnetic induction and cracked open a window onto a new world.

法拉第的感应环图

Faraday’s drawings of an induction ring

在空心线圈内来回移动条形磁铁，也能在导线中产生电流。奥斯特将电能转化为磁能，而法拉第则将磁能转化为电能——制造出了第一台简易的发电机，这是他十年前发明的电动机的机械逆过程。电能可以用来产生运动，运动也可以产生电能。正如爱因斯坦后来所说，在现实的表象之下，隐藏着某种东西。科学家的任务就是将其挖掘出来。

Moving a bar magnet back and forth inside a hollow coil also generated a current in the wire. Oersted had converted electricity into magnetism, and now Faraday had converted magnetism into electricity—producing the first crude electrical dynamo, the mechanical inverse of the motor he had devised ten years before. Electricity could be used to produce motion, and motion to produce electricity. Deep beneath the surface of reality, as Einstein would later say, something lay hidden. The job of the scientist was to coax it out.

法拉第观察得越仔细，就越明白其中的奥妙。他注意到，随着时间的推移，伏打电池中的铜电极会慢慢被氧化锌污染，而锌电极则会被铜覆盖。电池两极的电流流动必然伴随着原子内部的运动。这不仅为一种前景广阔的工业工艺——金属包覆铜或镀银——奠定了基础，而且这一现象还指向了另一个深刻的联系。电池就像一个熔炉，可以将一种能量——化学能——转化为另一种能量——电能。反过来也是如此。当两根带电导线（正极和负极）浸入微咸的溶液中时，氢气会聚集在一极，氧气会聚集在另一极。电流引发化学反应，而化学反应又产生电流。

The closer Faraday looked, the more he understood. He had noticed that over time, the copper electrodes in his voltaic cells slowly become tainted with zinc oxide, while the zinc electrodes became coated with copper. The flow of electricity from the battery’s two poles must be accompanied by an internal movement of atoms. Not only was this the basis for a promising industrial process—copper-cladding or silverplating a piece of metal: the phenomenon also pointed toward another deep connection. A battery was a crucible for turning one kind of energy—chemical—into another kind: electrical. The process also worked the other way. When two electrified wires, positive and negative, were immersed in a slightly salty solution, hydrogen accumulated at one pole and oxygen at the other. Electricity was producing chemical reactions, and chemical reactions were producing electricity.

整个欧洲的科学家都在努力解开这些谜团。水是由氢和氧构成的吗？或者，正如一位德国科学家提出的，水是元素——氧是由它与正电荷结合而成，氢是由它与负电荷结合而成？他甚至试图复兴燃素说。法拉第比任何人都更清晰地阐明了这些谜团。在整个19世纪30年代，他通过一系列实验证明了电、磁和化学之间的联系。然而，就在艾达·洛芙莱斯开始研究之前几年，他的研究陷入了低谷。

Scientists all over Europe were confronting these mysteries. Was water made from hydrogen and oxygen? Or, as a German scientist proposed, was water elemental—with oxygen made from combining it with positive electricity and hydrogen from combining it with negative electricity? He even tried to revive the phlogiston theory. It was Faraday, more than anyone, who cut through the confusion. Throughout the 1830s he demonstrated in one experiment after another how electricity, magnetism, and chemistry all were related. Then, a few years before Ada Lovelace began her pursuit, he fell into a slump.

他长期以来一直抱怨记忆力不好。如今，他陷入了深深的抑郁之中，无法集中注意力，还经常感到头晕目眩。或许是精神疲劳所致，又或许是长期接触化学物质造成的累积性中毒。遵照医嘱，他开始拒绝演讲邀请和工业研究的请求，将自己主要用于写作和沉思。与教会决裂——显然是因为某种派系纷争——加剧了他的孤立。随后，洛夫莱斯夫人用斜体字写满了奉承的辞藻，诱惑之大令他别无选择，只能断然拒绝：“你的邀请让我绝望，”他恳求道，“我不敢，也绝不能去，却又几乎无法拒绝。”

For a long time he had complained of problems with his memory. Now he was receding into a dark depression, unable to concentrate, suffering from dizzy spells. Maybe the cause was mental fatigue—or cumulative poisoning from all the chemicals that had touched his skin. On doctor’s orders he began turning down speaking invitations and requests for industrial research, confining himself mostly to writing and contemplation. A falling-out with his church—apparently over some kind of factional dispute—added to his isolation. Then came the barrage of italicized flattery from Lady Lovelace, tempting him so strongly that he felt he had no recourse but to cut it off: “You drive me to desperation by your invitations,” he pleaded. “I dare not and must not come and yet find it almost impossible to refuse.”

或许说他与“科学新娘”的近距离接触是人生的转折点有些夸张，但正是在这个时候，阴霾开始散去。精疲力竭的法拉第回到实验室，着手研究一个困扰他多年的问题。现在他清楚地认识到，电和磁密切相关。但是，电和光之间是否也存在某种联系呢？

Maybe it is too great a reach to say that his close encounter with the Bride of Science was a turning point, but it was around this time that the clouds began to lift. Faraday, a burnt-out case, returned to his laboratory to take up a question that had been gnawing at him for years. It was clear now that electricity and magnetism were tightly related. But could there also be a connection between electricity and light?

作为三一灯塔管理处（Trinity House）的科学顾问，法拉第致力于改进英格兰和威尔士沿海灯塔使用的强力阿根特油灯。三一灯塔管理处是亨利八世于1514年特许成立的机构，“旨在规范国王水域的船舶航行”。1845年8月下旬，他在实验室里点燃了一盏灯塔，为他日后最伟大的实验奠定了基础。

As scientific adviser to Trinity House, an organization chartered in 1514 by Henry VIII “so that they might regulate the pilotage of ships in the King’s streams,” Faraday had worked to improve the powerful Argand oil lamps used in the lighthouses along the English and Welsh coasts. In late August 1845, he fired up one of the beacons in his laboratory and prepared the way for what would become his most beautiful experiment.

光在传播过程中会横向振动——振动方向与其传播方向垂直。但如果光从平面反射或穿过某些晶体（例如电气石），它就会发生偏振，其振动被限制在一个平面内。

As light travels it vibrates transversely—at right angles to its direction of motion. But if it is reflected from a flat surface or passed through certain crystals like tourmaline, it becomes polarized, its oscillations confined to a single plane.

如果你透过第二个偏振晶体观察其中一束光束，同时将其旋转 360 度，随着滤光片的同步和不同步移动，图像会从亮变暗再变亮。

If you looked at one of these beams through a second polarizing crystal while rotating it through 360 degrees, the image would go from light to dark to light again as the filters moved in and out of sync.

法拉第现在提出的问题是，电流能否使光束发生扭曲，使其振动平面旋转。他将一个长槽装满一种弱导电溶液，在槽的两端放置铂电极，并将它们连接到一个五节电池上。这套装置类似于将水分解成组成气体或在勺子上镀铜的装置。他点亮阿根灯，并将灯光反射到一块玻璃板上，使光束发生偏振。然后，他将光束穿过通电的溶液，并使用一种叫做尼科尔棱镜的装置再次检查偏振情况。

The question Faraday now posed was whether an electrical current could twist a light beam, making its plane of vibration rotate. Filling a long trough with a mildly conducting solution, he placed platinum electrodes at each end and connected them to a five-cell battery. The setup was similar to what one might use to decompose water into its constituent gases or to copperplate a spoon. He lit the Argand lamp and reflected its light off a glass plate, causing it to become polarized. Then he passed the beam through the same solution where electricity was flowing and rechecked the polarization using a device called a Nicol prism.

反射偏振和通过偏振晶体偏振

Polarization by reflection and through a polarizing crystal

什么也没发生：振动方向没有改变。他尝试了连续电流、间歇电流以及电流流经各种溶液等实验方法，但都没有观察到任何效果。他又尝试让光束平行于电流方向照射，而不是垂直于电流方向照射。极化方向仍然没有改变。他猜测可能是电池电量不足，于是用静电发生器再次尝试，给一块玻璃板充电，然后让光束以各种角度照射。结果仍然没有变化。

Nothing happened: the direction of vibration was unchanged. He tried the experiment with continuous currents, with intermittent currents, with currents passed through various solutions, but there was no perceivable effect. He tried shining the light beam parallel to the electrical flow instead of across it. Still no shift in polarization. Speculating that his batteries were not strong enough, he tried again with a static electricity generator, charging a plate of glass and shining the light beam through it every which way. Still nothing.

这时，他决定尝试磁力实验。他从自己的材料堆里取出一块大约两英寸见方、半英寸厚的厚重光学玻璃，将其安装在强力电磁铁的磁极旁边。他调整灯泡和偏振片的位置，使水平光波能够穿过玻璃的整个长度。透过尼科尔棱镜观察，他旋转棱镜，直到光束消失。然后他接通电流。火焰的影像突然再次出现。他关闭磁铁，火焰再次消失。磁场使光束发生旋转。

It was then that he decided to try magnetism. Retrieving from his stockpile a heavy piece of optical glass about two inches square and half an inch thick, he mounted it next to the poles of a powerful electromagnet. He arranged the lamp and polarizing surface so that horizontal light waves passed through the length of the glass. Looking through the Nicol prism, he rotated it until the beam was extinguished. Then he switched on the current. The image of the flame suddenly reappeared. He turned the magnet off and the flame disappeared again. The magnetic field was making the light beam turn.

偏振实验。一块方形玻璃片（左图）分别贴在电磁铁的南北极上。一束偏振光束穿过玻璃片后，会因电磁场的作用而发生旋转。摘自法拉第日记

The polarization experiment. A square of glass (left) is placed against the opposing poles, north and south, of an electromagnet. A polarized light beam passing through the glass is rotated by the electromagnetic field. From Faraday’s diary

他之前在磁学和电学领域的研究正达到顶峰。他全身心投入研究，兴奋不已。“我现在除了工作几乎没有一刻空闲，”他写信给一位同事说，“我碰巧发现了磁与光、电与光之间的直接联系——而且它所揭示的领域如此广阔，我认为也如此丰富，所以我自然想先研究它……我其实没时间告诉你这是什么——因为我现在除了工作什么也不见，也不见任何人。”

All his previous work with magnetism and electricity was coming to a climax. With the exhilaration that comes from total absorption, he threw himself into his research. “At present I have scarcely a moment to spare for any thing but work,” he wrote to a colleague. “I happen to have discovered a direct relation between magnetism & light also Electricity & light—and the field it opens is so large & I think rich that I naturally wish to look at it first…. I actually have no time to tell you what the thing is—for I now see no one & do nothing but just work.”

法拉第发现，磁场的排列至关重要。当他把北极放在玻璃的一侧，南极放在另一侧时，什么也没发生。当他把玻璃的两面分别暴露在同极磁场下，或者把同极排列在同一侧时，也没有任何效果。“但是，”他在日记中写道（就像肾上腺素飙升的艾达·洛芙莱斯一样，他把“但是”这个词划了三下），“当相反的磁极在同一侧时，偏振光线就会产生影响，由此证明了磁力和光之间存在联系。”

The alignment of the magnetic field, Faraday learned, was paramount. Nothing happened when he placed a north magnetic pole on one side of the glass and a south pole on the other. Nor was there any effect when he exposed the two sides of the glass to similar poles, or when the same poles were lined up on the same side. “BUT,” he wrote in his diary (like Ada Lovelace on adrenaline, he underlined the word three times), “when contrary magnetic poles were on the same side, there was an effect produced on the polarized ray, and thus magnetic force and light were proved to have relation to each other.”

他证实，强力永磁体也能使光束旋转，而且可以用其他透明材料代替玻璃。有些材料效果更好，有些则不然，但无论如何，旋转角度都取决于磁场的强度。如果磁场的极性反转，光束也会朝相反的方向旋转。至此，整个图景的最后一根线被拉了上来。电与磁、磁与光交织在一起。

He confirmed that a powerful permanent magnet would also rotate the beam and that other transparent materials could be used in place of glass. Some worked better than others, but in every case the degree of rotation depended on the strength of the magnetic field. And if the polarity of the field was reversed, the light beam turned the other way. The final thread had been pulled into the tapestry. Electricity was entwined with magnetism and magnetism with light.

二十年后，詹姆斯·克拉克·麦克斯韦用他著名的方程式证明了光是电磁力。法拉第几乎没有停顿，便试图进一步推进统一理论，将引力与磁力联系起来，但这一探索最终未能成功，他和爱因斯坦以及此后的每一位科学家都未能做到。“这一切都像一场梦，”他在日记中写道，“只要符合自然规律，就没有什么奇迹是不可能实现的。而对于这类事情，实验是检验其一致性的最佳方法。”

It was left for James Clerk Maxwell, two decades later, to show with his famous equations that light is electromagnetism. With barely a pause Faraday tried to push the unification further, attempting to connect gravity with magnetism, a quest that eluded him and Einstein and every scientist since. “ALL THIS IS A DREAM,” he wrote in his diary. “Nothing is too wonderful to be true, if it be consistent with the laws of nature, and in such things as these, experiment is the best test of such consistency.”

在这一切之中，艾达始终萦绕在他的心头。“你看，你对我做什么都随心所欲，”1851年，在他苦苦哀求她离开六年之后，他写信给她。“你说写，我就写——我多么希望自己有足够的精力和休息，能写更多。”第二年，她因宫颈癌去世，年仅三十六岁。法拉第比她多活了十五年。

Throughout all this, Ada was still in his mind. “You see what you do—ever as you like with me,” he wrote to her in 1851, six years after he had begged her to go away. “You say write & I write—and I wish I had the strength and had rest enough for a great deal more.” The next year she died of cervical cancer. She was thirty-six. Faraday outlived her by fifteen years.

第七章

CHAPTER 7

詹姆斯·焦耳

James Joule

世界如何运转

How the World Works

詹姆斯·普雷斯科特·焦耳

James Prescott Joule

因此，您或许会惊讶地发现，直到最近，人们普遍认为生命力可以完全且不可逆转地被任何人摧毁。例如，当重物坠落到地面时，人们通常认为它的生命力就此彻底消失，之前将其举到高处所付出的努力也完全白费了，没有产生任何永久性的影响。

You will therefore be surprised to hear that until very recently the universal opinion has been that living force could be absolutely and irrevocably destroyed at any one’s option. Thus, when a weight falls to the ground, it has been generally supposed that its living force is absolutely annihilated, and that the labour which may have been expended in raising it to the elevation from which it fell has been entirely thrown away and wasted, without the production of any permanent effect whatever.

——詹姆斯·焦耳，1847年曼彻斯特演讲

—James Joule, lecture in Manchester, 1847

我们无从得知威廉·汤姆逊在1847年8月那个阴沉的日子里，从霞慕尼徒步前往圣热尔韦时究竟在想些什么，但很可能与物理学有关。这位神童在16岁时就发表了他的第一篇科学论文。22岁刚从剑桥大学毕业，他就被任命为格拉斯哥大学的自然哲学教授。一年后，他徒步穿越法国阿尔卑斯山，前往勃朗峰。汤姆逊逐渐相信，自然界的一切力量必然是相互关联的（他仿佛“接种了法拉第火疫苗”），或许当他接近通往博诺姆山口高山步道的岔路口，遇到另一位徒步者詹姆斯·普雷斯科特·焦耳那张熟悉的面孔时，他正在思考着这个问题。

WE DON’T know what William Thomson was thinking on that cloudy August day in 1847 as he set out on foot from Chamonix toward Saint Gervais, but it probably had something to do with physics. A child prodigy, he had published his first scientific paper when he was sixteen. Fresh out of Cambridge at twenty-two, he was named to the chair of natural philosophy at the University of Glasgow, and now, a year later, was trekking in the French Alps bound for Mont Blanc. All the forces of nature, Thomson was coming to believe, must be related (he had been “inoculated with Faraday fire”), and he may have been turning that thought over in his head as he approached the turnoff for the high trail over the Col du Bonhomme and encountered the familiar face of another hiker, James Prescott Joule.

焦耳当时正在度蜜月（他的妻子乘马车跟在后面），据汤姆逊后来回忆，他当时带着一根长长的温度计，用来测量瀑布的温度。如果焦耳的理论正确，那么瀑布底部的水温必定比顶部的水温略高，这意味着当时盛行的热理论——汤姆逊认为最令人费解的自然力——是错误的。他同意几天后在“萨朗什瀑布”（Cascade de Sallanches）与焦耳会面——这很可能就是1199英尺高的阿尔佩纳兹瀑布，根据焦耳的计算，瀑布底部和顶部的水温应该相差大约华氏1.5度。汤姆逊报告说，当时水雾太大，无法准确测量。两人一无所获，各自离开了。

Joule was on his honeymoon (his wife was following behind in a carriage), and he was carrying, or so Thomson would later remember, a long thermometer with which to measure the temperature of waterfalls. If Joule was right, the water at the bottom of a fall must be slightly warmer than the water at the top, and this would mean that the prevailing theory of heat, the one force of nature Thomson found most puzzling, was incorrect. He agreed to meet up with Joule a few days later at the “Cascade de Sallanches”—probably the 1,199-foot Arpenaz waterfall, which by Joule’s reckoning should show a temperature difference of roughly one and a half degrees Fahrenheit. There was too much spray to take an accurate reading, Thomson reported. Dataless, the two men went their separate ways.

这个故事或许过于完美了。尽管汤姆逊（未来的开尔文勋爵）确实在小径上遇到了焦耳，但几天后他从大圣伯纳德医院写给父亲的信中却只字未提温度计。记忆往往会混淆。很可能多年后，当开尔文——当时已是欧洲最受尊敬的科学家之一——描述这次偶遇时，他把这件事和之前发生的一件事混淆了。

The story is probably a little too neat. Though he did meet Joule on the trail, Thomson, the future Lord Kelvin, made no mention of the thermometer when he wrote to his father a few days later from the Hospice du Grand-Saint-Bernard. Memories have a way of becoming mushed together. It seems likely that years later, when Kelvin, by then one of the most revered scientists in Europe, described the encounter, he was conflating it with an earlier event.

两个月前，他们在牛津的一次科学会议上初次相遇。焦耳是一位来自工业城市曼彻斯特的自学成才的业余科学家，他的想法常常被人忽视。因此，当他演讲结束时，一位名叫汤姆逊的年轻人站起来，提出了一些精辟的见解，这让他欣喜不已。焦耳性格内向腼腆，不善言辞，并不擅长演讲，但至少有人认真听了他的发言。汤姆逊后来坚称，他当时一直坐在座位上，只是在演讲结束后才提问。或许这次焦耳的记忆出了错，但他所描述的实验显然给汤姆逊留下了深刻的印象。

Their paths had first crossed two months earlier at a scientific meeting in Oxford. Accustomed to having his ideas ignored, Joule, a self-taught amateur from the industrial city of Manchester, was delighted when at the end of his talk this young man named Thomson stood up and made some acute observations. Joule was too awkward and reserved to make a good lecturer, but at least someone had been listening. Thomson would later insist that he had remained seated and asked his questions only afterward. This time maybe Joule’s memory was playing tricks, but the experiment he described had clearly made an impression.

拉瓦锡虽然打破了虚构的燃素的束缚，但在去世前，他又提出了另一项发明：热质，这是他为一种无形物质——一种“微妙的流体”——命名的，据说它是热量的载体。这个想法似乎合情合理。热的物体富含热质，而热质具有膨胀的趋势，因此它自然会向密度较低的地方迁移。把一根金属拨火棍放入火中，热质会沿着棍身上升，直到你能感觉到手柄的温度。物体受热膨胀是因为它们吸收了热质。气体受压时温度升高，是因为其中的热质浓度增加；气体稀薄时温度降低，是因为热质扩散开来。

Lavoisier had loosened the grip of the fictional phlogiston, but before his death he introduced another invention: caloric, his name for an invisible substance—a “subtle fluid”—said to be the carrier of heat. The idea seemed sensible enough. Something that was hot was dense with caloric, and because caloric had a tendency to expand, it would naturally migrate toward where it was not. Put a metal poker into a fire, and the caloric will rise up the shaft until you can feel the warmth in the handle. Things expanded when they were heated because they took in caloric. Gases got hotter when compressed because the caloric within them became more concentrated, and they cooled as they rarefied because the caloric spread out.

在蒸汽机中，热量甚至可以像水在磨坊中一样被利用来做功。热量集中在燃烧的煤块中，流入锅炉，加热水，并随蒸汽推动活塞运动。循环结束后，等量的热量作为废气排放到空气中。如同物质一样，热量既不能被创造，也不能被消灭。宇宙被赋予了固定的热量总量，它不断地在宇宙中循环流动。

In a steam engine, caloric could even be harnessed, like water in a mill, to do work. Concentrated in lumps of burning coal, caloric flowed into the boiler, heated the water, and was carried with the steam that pushed the piston. When the cycle was complete the same amount was expelled into the air as exhaust. Like matter, caloric could be neither created nor destroyed. The universe had been bequeathed with a fixed amount that was constantly being shuttled from place to place.

这就是汤姆逊为何对焦耳的演讲感到如此不安的原因。焦耳声称他证明了热量可以随意产生。当天晚些时候，在博德利图书馆优雅的圆顶圆柱形附属建筑——拉德克利夫图书馆举行的招待会上，他们讨论了这一发现的意义。“我确信焦耳的许多观点都是错误的，”几天后，汤姆逊写信给父亲说，“但他似乎发现了一些极其重要的事实。”不久之后，焦耳又给这位新朋友写了一封信，建议可以用一根绳子、一个水桶和一个好的温度计来证明，即使是落水也会产生热量。

That is why Thomson had found Joule’s presentation so unsettling. Joule claimed to show that heat could be created at will. At a reception later that day at the Radcliffe Camera, the elegantly domed cylindrical annex of the Bodleian Library, they discussed the implications. “Joule is, I am sure, wrong in many of his ideas,” Thomson wrote to his father a couple of days later, “but he seems to have discovered some facts of extreme importance.” Not long afterward, Joule followed up with a letter to his new friend suggesting how a rope, a bucket, and a good thermometer could be used to show that heat was generated even by falling water.

焦耳并非第一个挑战“热是一种不可见流体”这一观点的科学家，而拉瓦锡，或者更确切地说是他的遗孀玛丽·安妮，再次出现在我们的故事中。她也曾身陷囹圄，但在罗伯斯庇尔倒台后，她重新夺回了拉瓦锡的庄园，并再次主持起一个奢华的沙龙，欧洲一些顶尖的思想家经常光顾。她的客人之一是本杰明·汤普森，一位美国流亡者，他在革命中败北，被迫逃往伦敦，抛弃了妻子和女儿。后来他移居巴伐利亚，获得了伦福德伯爵的爵位。1801年，他遇到了玛丽·安妮，并决心将她也纳入麾下。他写道，她活泼、善良、聪慧，虽然正如他委婉地形容的那样，她“身材丰腴”（en bon point），但“她的个人财富相当可观”。

JOULE was not the first scientist to challenge the notion that heat is an invisible fluid, and here Lavoisier, or rather his widow, Marie Anne, enters our story one last time. She too had spent time in prison, but after Robespierre’s fall had reclaimed the Lavoisier estate and was presiding again over a lavish salon frequented by some of Europe’s premier thinkers. One of her guests was Benjamin Thompson, an American exile who had found himself on the losing side of the Revolution and had fled to London, abandoning his wife and daughter. He later moved to Bavaria where he acquired a title, Count Rumford, and after he met Marie Anne, in 1801, was determined to acquire her as well. She was lively, kind, and intelligent, he wrote, and though she was, as he delicately put it, rather “en bon point” (pleasingly plump), “her personal fortune is considerable.”

这位伯爵傲慢而喜怒无常，他自己也并非什么好人（他的前妻也是一位富有的寡妇），他一定意识到，要赢得玛丽·安妮的芳心，就必须先攻其智。他用自己在科学领域的成就来追求她，其中许多都与热有关——发明了伦福德炉、保暖内衣、滴滤咖啡壶，以及最重要的，第一个广为人知、对热量理论提出质疑的实验。

Arrogant and moody, the count was no prize himself (his previous bride had also been a rich widow), and he must have sensed that the way to Marie Anne’s heart was through her brain. He courted her with tales of his scientific feats, many of which had to do with heat—the invention of the Rumford stove, thermal underwear, a drip coffeepot, and most significantly the first widely known experiment to cast doubt on the caloric theory.

在为巴伐利亚军方工作期间，拉姆福德对钻黄铜大炮时产生的热量印象深刻。当时人们普遍认为钻孔会释放金属中储存的热能，但拉姆福德对此表示怀疑。他将一门大炮浸入水中，并用两匹马拉动钻头。水温不断升高，两个半小时后，水沸腾了，“仅仅依靠一匹马的力量，既没有火，也没有光，没有燃烧，也没有化学分解。”

While working with the Bavarian military, Rumford had been impressed by how much heat was produced by boring out the holes of brass cannons. Conventional wisdom held that the drilling was liberating caloric that was trapped in the metal, but Rumford was dubious. He submerged a cannon in water and harnessed two horses to turn the bit. The water got hotter and hotter until after two and a half hours it came to a boil “merely by the strength of a horse, without either fire, light, combustion, or chemical decomposition.”

“很难描述旁观者脸上流露出的惊讶和震惊，他们看到如此大量的冷水被加热，而且竟然在没有火的情况下沸腾了，”他向皇家学会报告说。他认为，只要马匹还能坚持，他就能持续产生更多的热量。如果真有热量这种东西，那么这门大炮似乎就蕴藏着取之不尽的热能。

“It would be difficult to describe the surprise and astonishment expressed in the countenances of the by-standers, on seeing so large a quantity of cold water heated, and actually made to boil without any fire,” he reported to the Royal Society. He saw no reason to doubt that, as long as the horses lasted, he could keep on churning out more heat. If there was such a thing as caloric, the cannon itself seemed to hold an inexhaustible supply.

其他人也得出了类似的结论：热并非物质，而是一种“生命力”（vis viva ）或运动——正如罗伯特·胡克所写，“是物体各部分非常剧烈而活跃的振动”。瑞士数学家丹尼尔·伯努利曾提出，热是肉眼不可见的微小物质粒子的振动。但那是一种日渐式微的理论，而拉姆福德的实验精度也不足以改变许多人的看法。

Others had come to a similar conclusion: that heat is not a material thing but some kind of vis viva (“living force”) or motion—“a very brisk and vehement agitation of the parts of a body,” Robert Hooke had written. The Swiss mathematician Daniel Bernoulli had proposed that heat was the vibration of invisibly tiny particles of matter. But that was a dying theory, and Rumford’s experiment hadn’t been done with enough precision to change many minds.

经过四年的追求，拉姆福德终于说服玛丽·安妮嫁给他，并搬进了她的豪宅。然而，这段婚姻并没有长久。一天，拉姆福德嫉妒玛丽·安妮的独处，禁止她招待客人。玛丽·安妮为了报复，将滚烫的开水泼洒在他的玫瑰花上。最终，她支付了拉姆福德30万至40万法郎，让他离开。

After a four-year courtship, Rumford persuaded Marie Anne to be his wife and moved into her mansion. The marriage didn’t last. One day, jealous of his solitude, he barred her guests from the house. She retaliated by pouring boiling water, rich in caloric, on his roses. Finally she paid him 300,000 to 400,000 francs to go away.

在十九世纪初的几十年里，当法拉第等实验家们探索出隐藏的电磁联系时，热的本质——这种如此熟悉、平凡却又威力无穷的东西——却依然晦涩难懂。不知何故，这种神秘的“虚无”在蒸汽机中传递时，竟能撼动大地。蒸汽驱动的水泵从矿井中抽取大量的水，露出深层的煤层，这些煤层驱动着火车、工厂和磨坊运转。蒸汽铲挖掘出大量的铁矿石，用于锻造更多的工具和机械。有了如此丰富且便于携带的动力来源，沿着英格兰北部磨坊溪流兴起的小型水力驱动工业经济开始向南扩展到平原地区。在焦耳1818年出生的曼彻斯特，蒸汽机很快便随处可见，它们冒着浓烟，转动着车轮。这些装置的基本原理早已被人们所理解——高压蒸汽推动活塞，活塞通过齿轮带动轮子转动——但没有人知道是什么自然规律使这一切成为可能。就好像后来的核反应堆是在人们完全不了解其中物理原理的情况下，通过反复试验才研制出来的一样。

DURING THE FIRST decades of the nineteenth century, as experimenters like Faraday teased out hidden electromagnetic connections, the nature of heat—so familiar, mundane, and powerful—remained stubbornly obscure. Somehow in its passage through a steam engine, this mysterious nothing could literally move the earth. Steam-driven pumps sucked tons of water from mine shafts, exposing deep veins of coal that would drive locomotives, factories, and mills. Steam shovels excavated lodes of iron ore from which to forge more tools and machinery. With a source of power so abundant and portable, a small water-driven industrial economy that had sprouted along northern England’s millstreams began spreading southward into the flatlands. In Manchester, where Joule was born in 1818, there were soon steam engines everywhere, belching smoke and turning wheels. The basic principle of these devices was well understood—a head of high-pressure steam pushed a piston that was geared to turn a wheel—but no one knew what laws of nature made this possible. It was as though, later on, the nuclear reactor had been developed through trial and error without anyone understanding the physics.

詹姆斯·瓦特于十八世纪晚期制造的蒸汽机

A late-eighteenth-century steam engine made by James Watt

旧河边磨坊的运作原理似乎很清楚。水流从桨轮顶端急速奔涌，向下倾泻，然后以较慢的速度从底部流出。水流的一部分“动力”（或称“动能”）用于驱动桨轮转动。进出水流速度的差异越大，从瀑布中提取的能量就越多。

It seemed clear enough what was happening in the old riverside mills. Water flowed rapidly at the top of a paddle wheel, fell downward, and emerged at the bottom at a slower pace. Some of its “effort,” or vis viva, was spent turning the wheel. The greater the difference between the incoming and outgoing velocities, the more power was extracted from the waterfall.

水车

A water wheel

像法国人拉扎尔·卡诺这样的工程师曾研究过如何使水磨坊的效率达到最高。1824年，他的儿子萨迪·卡诺（以一位波斯诗人的名字命名）提出了一个类比：蒸汽机就像一个桨轮，只不过水被热量取代，热量沿着从高温到低温的梯度“下降”。他在一篇当时鲜为人知的论文《论火的动力》中阐述了他的理论。蒸汽以极高的温度进入发动机，以较低的温度排出。通过最大化温差，人们可以从燃料中榨取物理定律允许的最大能量。人们也可以反向运行这个循环：做功将热量泵回高温区域（就像现代冰箱利用从墙壁插座吸取的电力一样）。

Engineers like the Frenchman Lazare Carnot had studied how to make water mills as efficient as possible. In 1824 his son, Sadi Carnot, named for a Persian poet, went on to propose an analogy: a steam engine is like a paddle wheel with the water replaced by caloric “falling” down a gradient from hot to cold. He described his theory in a treatise, little known at the time, called Reflections on the Motive Power of Fire. Steam entered the engine at a very high temperature and exited at a much lower one. By maximizing the difference one could squeeze as much work from the fuel as physics allowed. One could also run the cycle backward: performing work to pump heat back uphill (what a modern refrigerator does with the power it sucks from the wall outlet).

卡诺的分析标志着开尔文后来称之为热力学的开端，但它仍然保留了热是一种物质——热质——的观点，就像水流过水车一样，既不会被创造也不会被消灭。焦耳少年时期很可能从他的导师约翰·道尔顿那里学到了这一切。道尔顿也是曼彻斯特居民，他的化学实验奠定了现代原子理论的基础。焦耳的父亲是一位富有的酿酒商，他安排詹姆斯和他的兄弟跟随这位化学家进行私人学习。詹姆斯很快就展现出对科学的热情，他用莱顿瓶电击他的玩伴，并在跛脚的马和女仆身上进行电学实验，女仆被电得昏了过去。到了十九岁，在酿酒厂工作的他开始摆弄线圈和磁铁，希望能发明一种比蒸汽机更强大、运行成本更低的电动机。

Carnot’s analysis marked the beginning of what Kelvin would name thermodynamics, but it left intact the idea that heat was a substance—caloric—that, like water passing through a water wheel, was neither created nor destroyed. As a teenager, Joule probably learned all this from his tutor, John Dalton, another Manchester resident, whose chemistry experiments had established the foundation of modern atomic theory. Joule’s father, a prosperous brewer, had arranged for James and his brother to study privately with the chemist. Quickly becoming the eager boy scientist, James shocked his playmates with Leyden jars and experimented with electricity on a lame horse and on a servant girl, who received such a jolt that she fainted. By the time he was nineteen, working at the brewery, he was tinkering with coils and magnets, hoping to invent an electric motor more powerful than a steam engine yet cheaper to run.

为了给装置供电，焦耳使用了伏打电池，其中两个电极——一个锌电极和一个铜电极——浸入稀硫酸中。在这种电池中，硫酸会腐蚀锌电极，释放出过量的电子。将电机连接到电池的两极之间，就会产生电流，使线圈磁化，从而带动转子旋转。

To power the device, Joule used voltaic cells in which two electrodes—one zinc and one copper—were immersed in dilute sulfuric acid. In a battery like this, the acid eats away at the zinc releasing an excess of electrons. Connect a motor across the poles and a current will flow, magnetizing the coils that make the rotor spin.

焦耳很早就注意到，电磁铁的磁力与电流的平方成正比。电池数量翻倍，磁力就能增加四倍。他认为，同样的规律也可能适用于电动机，这在当时一定如同20世纪80年代的冷聚变一样令人震惊。“我几乎可以肯定，电磁力最终会取代蒸汽来驱动机械，”焦耳兴奋地宣称，仿佛一个二十岁的年轻人还未曾经历过物质世界的种种烦恼。“发动机的运行成本可以无限降低。 ”他认为，除了空气阻力和摩擦等微小的阻碍之外，“似乎没有什么能够阻止极高的旋转速度，从而产生巨大的动力。”

Early on, Joule noticed that the strength of an electromagnet increased as the square of the current. By doubling the number of batteries, you quadrupled the power. The possibility that the same might be true for an electric motor must have seemed as stunning as cold fusion did in the 1980s. “I can hardly doubt that electro-magnetism will ultimately be substituted for steam to propel machinery,” Joule declared with the enthusiasm of a twenty-year-old unused to the troubles posed by the material world. “The cost of working the engine may be reduced ad infinitum.” Except for minor impediments like air resistance and friction, he believed, “there seemed to be nothing to prevent an enormous velocity of rotation, and consequently an enormous power.”

现实并非如此顺遂。焦耳的第一台电动机动力微弱，几乎无法自转。他尝试了不同的线圈和电池组合，用不同类型的导线缠绕不同类型的磁芯，但始终无法突破自然规律。输入电动机的电流越大，线圈的温度就越高。事实上，焦耳发现，温度的增加还遵循平方定律。电池数量翻倍，温度就会增加四倍。这注定是徒劳的。残酷的现实是，你不可能从一个系统中获取比输入更多的能量。你只能将能量转换成另一种形式。

Reality was not so compliant. Joule’s first motor was barely powerful enough to turn itself over. He tried different arrangements of coils and batteries, and wrapped different kinds of wire around different kinds of cores, but he continued to run up against nature’s will. The more current you fed to the motor, the hotter its coils became. In fact Joule discovered that the heat also increased according to the rule of squares. If you doubled the number of batteries you quadrupled the heat. It was a losing proposition. The hard truth was that you cannot get more energy out of a system than you put into it. You can only convert the energy into a different form.

到1841年，这一教训已深入人心。当时世界上最好的蒸汽机能从一磅煤中榨取足够的能量，将150万磅的重物提升到离地一英尺的高度——或者说，将一磅重的物体提升到离地150万英尺的高度。换句话说，一磅煤能做150万英尺磅的功。焦耳最好的电池驱动马达从一磅锌中只能提取出煤的五分之一的能量，而锌的价格却是煤的六七十倍。“这种比较如此不利，”他叹息道，“以至于我几乎对电磁吸引力作为一种经济的能源能否成功感到绝望。”

By 1841, the lesson had thoroughly sunk in. The best steam engines in the world could sap enough vis viva from a pound of coal to lift 1.5 million pounds one foot off the ground—or one pound 1.5 million feet off the ground. A pound of coal, in other words, was doing 1.5 million foot-pounds of work. Joule’s best battery-powered motor could extract only one fifth as much from a pound of zinc, and zinc cost sixty to seventy times more than coal. “The comparison is so very unfavourable,” he lamented, “that I confess I almost despair of the success of electro-magnetic attractions as an economical source of power.”

焦耳的电动机。摘自他的科学论文。

Joule’s electric motor. From his Scientific Papers

当然，如今世界各地的工厂里，由电网供电的电动机已经取代了蒸汽机。但归根结底，它们的能量仍然来自蒸汽。在发电厂里，煤炭或天然气燃烧，或者铀裂变产生蒸汽来加热水，从而驱动涡轮机，涡轮机再带动发电机发电。

Today, of course, electric motors, powered by electricity from the grid, have supplanted steam engines in factories around the world. But ultimately their energy comes from steam. In a power plant, coal or gas is burned or uranium is fissioned to boil water, moving the turbines that drive the dynamos that make electricity.

对于从事电机制造这一实际工艺的人来说，热量固然令人烦恼，但焦耳开始意识到一个更深层次的真理：热量与功之间存在着根本的联系。一根导线如果短接在电池的两极之间，很快就会变得非常热，以至于绝缘层冒烟。但如果将电机接入电路，导线的温度就会降低：做功是以热量的形式进行的。用电池电解水，将其分解成氢气和氧气，或者给勺子电镀，情况也是如此。

TO A PERSON engaged in the practical craft of motor making, heat was a nuisance, but Joule was starting to sense a deeper truth: that there was a fundamental connection between heat and work. A wire shorted across the poles of a battery will quickly become so hot that the insulation smokes. But if you insert a motor into the circuit, the wire stays cooler: work is accomplished at the expense of heat. The same was true if you used the battery to electrolyze water, splitting it into hydrogen and oxygen, or to electroplate a spoon.

或许电池在释放电能的同时也释放了热量，但电池似乎并没有变冷——这进一步证明热量并非预先存在，而是瞬时产生的。1843年，焦耳开始对这一假设进行验证。

Maybe caloric was flowing from the battery, along with electricity, but the battery didn’t seem to get cooler—more evidence that the heat was not preexisting but generated on the fly. In 1843 Joule began putting the hypothesis to a test.

他的想法是将一个线圈放入装满水的绝缘玻璃管中，然后用手摇曲柄旋转它。旁边放置两个从焦耳电动机上拆下来的强力电磁铁。这样就形成了一个发电机。线圈的导线连接到电流计，用来测量产生的电流大小。（为了防止导线缠绕，他设计了一个由水银制成的离合器，水银位于两个半圆形凹槽内。）他会测量水的温度，然后稳定地转动曲柄十五分钟，再测量一次水温。

The idea was to place a coil inside an insulated glass tube filled with water and spin it with a hand crank. Sitting alongside would be two powerful electromagnets salvaged from Joule’s electrical engines. The result was a generator. The wires of the coil were connected to a galvanometer to measure how much current was produced. (To keep the wires from twisting he devised a clutch made from mercury sitting inside two semicircular grooves.) He would measure the temperature of the water, steadily turn the crank for fifteen minutes, and then take the temperature again.

焦耳发电机。图中未显示电磁铁。

Joule’s generator. The electromagnets are not shown.

这是一项非常精细的操作。他必须考虑空气的冷却效应和室温的变化等因素。他还必须考虑到旋转线圈中感应的电流并非恒定不变，而是呈脉动状。他尝试了不同强度的磁铁和不同数量的电池，最终得出结论：旋转确实使水温略微升高。通过比较电流计和温度计的读数，他发现了一个熟悉的规律：电流加倍，产生的热量就增加四倍。

It was a very delicate operation. He had to adjust for things like the cooling effect of the air and changes in room temperature. He had to allow for the fact that the current induced in the spinning coil was not steady but pulsating. He tried different strengths of magnets, different numbers of batteries, and when he was done he had persuaded himself that the spinning made the water slightly warmer. Comparing the readings from the galvanometer with those from the thermometer, he saw a familiar relationship: double the current and you get four times the heat.

线圈并未连接电池。那么热量从何而来？唯一可能的来源是焦耳转动曲柄所做的功。正如拉姆福德的大炮实验一样，圆周运动被转化为另一种运动——微小的物质振动，我们用手指感觉到的就是热量。

The coil was not connected to a battery. So where was the caloric coming from? The only possible source of heat was the work Joule was doing by turning the crank. As in Rumford’s cannon experiment, circular motion was being converted into a different kind of movement—tiny material vibrations our fingers feel as heat.

为了说服怀疑者，焦耳知道他必须更进一步。究竟需要多少英尺磅的功才能产生一定量的热量？他重新设计了最初的装置，用两根长绳缠绕手摇曲柄的轴，绳子的缠绕方向相反。每根绳子都挂在一个滑轮上，滑轮的另一端连接着一个装有重物的托盘。当重物下落时，线圈就会旋转，从而产生电能和热能。

To persuade the skeptics Joule knew he would have to go a step further. Precisely how many foot-pounds of work does it take to produce a given amount of heat? He redesigned his original apparatus, winding the axle of the hand crank with two long pieces of twine, coiling them in opposite directions. Each was slung over a pulley and attached to a pan that held a weight. As the weights fell, the coil would spin and generate electricity and heat.

他尝试了不同重量的物体从不同高度落下（为了给它们提供足够的空间，他在花园里挖了两个坑），估计一个838磅重的物体悬挂在离地一英尺处所储存的机械能产生的热量足以使一磅重的水升高华氏一度。按重量计算，一座838英尺高的瀑布——圭亚那的爱德华八世瀑布就接近这个高度——底部温度应该比顶部高大约一度。

After trying different weights falling from different heights (to give them enough room he dug two holes in his garden), he estimated that the mechanical effort stored in an 838-pound mass suspended a foot off the ground would produce enough heat to raise a pound of water by one degree Fahrenheit. Pound for pound, the temperature of a waterfall 838 feet high—King Edward VIII Falls in Guyana comes close—should be roughly one degree warmer at the bottom than at the top.

1843年8月，他在爱尔兰科克的一次科学会议上描述了他的研究成果，但正如他后来所说，“这个课题并没有引起广泛的关注”。各种现象——电、磁、热、运动——的交织或许掩盖了他报告的重点，而焦耳本人可能也难辞其咎。他仍然需要一个能够一目了然、不言自明的实验——一个更简单、更优雅、更清晰的实验。

In August 1843, he described his results at a scientific conference in Cork, Ireland, but, as he later put it, “the subject did not excite much general attention.” The tangle of different phenomena—electricity, magnetism, heat, motion—may have obscured the point of his presentation, and Joule himself probably didn’t help. He still needed a knockdown experiment that would speak for itself—one that was simpler, more elegant, with cleaner lines.

用于转动发电机曲柄的重物和滑轮

Weights and pulleys to turn the generator crank

1847年牛津会议召开时，焦耳已经完成了他的证明，并在会上结识了威廉·汤姆逊。当时已是傍晚时分，所以他被要求尽量简短地作答。他从曼彻斯特带回了新研制的装置，并将其摆放在讲堂的桌子上：这是一个铜包锡的容器。盖子也是锡制的，正中间开有一个孔，用来容纳黄铜桨轮的轴，还有一个孔用来插入温度计。

BY THE TIME of the Oxford meeting in 1847, where he met William Thomson, Joule had his proof in hand. It was late in the afternoon so he was asked to keep the presentation short. He had carried his new apparatus down from Manchester and set it up on a table in the lecture room: a vessel made of copper clad with tin. The lid, also tin, had a hole cut dead center to accommodate the shaft of a brass paddle wheel, and another hole in which to insert a thermometer.

焦耳解释了他如何将容器注满水，并设置好重物、绳索和滑轮来驱动桨叶转动。容器内壁周围的黄铜挡板阻碍了水的圆周运动，增加了摩擦力。他在每个托盘中放入一个29磅重的重物，将它们提升到离地5.25英尺的高度，然后让它们落下。接着，他重新卷起轴，再次让重物落下，如此重复了20次。总共，搅动水所做的功约为6090英尺磅：58磅重的重物被提升到105英尺（20 × 5.25）的高度。他总共进行了9次实验，最终发现水的温度平均升高了0.668度。

Joule explained how he had filled the vessel with water and rigged up the weights, strings, and pulleys to make the paddle turn. Around the inside wall of the container, brass baffles resisted the circular movement of the water, increasing the friction. Placing a 29-pound weight in each pan, he raised them 5.25 feet from the ground and let them fall. Then he rewound the spindle and let the weights fall again, repeating the procedure twenty times. All together, the work used to churn the water added up to about 6,090 foot-pounds: 58 pounds of weight raised 105 (20 × 5.25) feet high. He conducted the experiment a total of nine times, finding in the end that the temperature of the water had risen by an average of 0.668 degree.

焦耳实验的改进版本

The refined version of Joule’s experiment

他估计，下落的重物产生的部分力被滑轮和绳子的摩擦力抵消了。为了估算损耗量，他取了一个与纺锤直径相同的滚筒，将一段绳子绕在上面一圈，并将重物悬挂在滚筒的两端。他逐渐在滚筒的一侧增加较小的重物，发现大约需要7.2盎司（3150格令）的重量才能打破平衡，使轮子开始转动。

He figured that some of the force from the falling weights had been wasted overcoming the friction of the pulleys and string. To estimate how much, he took a roller of the same diameter as the spindle and wound a piece of the twine once around it, suspending his weights from both ends. Gradually adding smaller weights to one side, he found that it took about 7.2 ounces (3,150 grains) to upset the balance and cause the wheel to budge.

考虑到这些因素以及其他因素，他改进了之前的计算：将一磅水加热一度需要781.5英尺磅的力，后来他将这个数字修正为772英尺磅。反过来，一度的温差——如果你能利用它的话——就有可能将一磅重的物体提升到772英尺的高空。

Taking this and other factors into account, he improved on his earlier calculation: heating one pound of water by one degree took 781.5 foot-pounds of effort, a figure he would later refine to 772 foot-pounds. Conversely a one-degree difference in temperature had the potential—if only you could tap it—of raising a one-pound weight 772 feet in the air.

这一次，没有线圈和电池来混淆视听。热和功不仅相关，而且本质相同：它们是“努力”或“生命力”（我们现在称之为能量）转化为运动的两种不同方式。功是指用力使物体移动一段距离所产生的效果——例如马拉车。它是结构化的能量，被用于生产性用途。另一方面，热是无目的的功，它没有方向，没有结构，能量以随机的微观振动形式耗散。随着原子理论的不断发展，这一形象变得更加清晰：热是原子的振动。

This time there were no coils and batteries to muddy the message. Heat and work were not only related but the same: two different ways in which “effort” or vis viva—energy, we now say—was converted into motion. Work was what resulted when a force was used to move something across a distance—a horse pulling a wagon. It was structured energy put to productive use. Heat, on the other hand, was unproductive work, directionless, unstructured, energy dissipated as random microscopic vibrations. As atomic theory continued to develop, the image would become more vivid: heat is the vibration of atoms.

这是一个非凡的想法，当时人们对此还不太了解：焦耳将重物举离地面时消耗了一种叫做能量的东西，而当重物下落时，能量又会释放出来。如果将这种能量连接到发电机上，就可以将其转化为电能，用于驱动电动机，或者将水抽到高处的蓄水池，水流下来驱动水车，水车又可以用来给巨大的钟表发条上弦。但是，在能量传递的每一个环节，都会有一部分能量以热的形式散失。如果让重物自由下落而不做任何功，那么除了热量之外，你得到的就只有热量——来自它与地面的撞击以及空气阻力。真正需要守恒的不是热量，而是能量。

It was an extraordinary notion, just barely understood: Joule was expending this stuff called energy when he raised a weight off the ground, and when the weight fell it was giving the energy back. Harnessed to a generator, the work could be converted into electrical power, which might be used to run a motor and pump water uphill to a reservoir, where it could flow downward and turn a water wheel, which might be used to wind a giant clock spring. But at every step of the way, a portion of the energy would be lost as heat. And if the weight was simply allowed to fall with no work done, heat is all you would get—from the impact with the ground and the resistance of the air. It was not caloric that must always be conserved but energy.

汤姆逊接受了焦耳的发现后，便着手研究其含义。虽然宇宙中的热量并没有消失，但它逐渐衰减，从高温流向低温，再也回不去了——“永远地消失了”。

Once he accepted Joule’s discovery, Thomson went on to work out the implications. Though heat didn’t disappear from the universe, it gradually became degraded, flowing from hot to cold and never back again—“irrecoverably lost.”

他意识到，这意味着世界曾经非常炎热，并且不可避免地会变得越来越冷：“在过去的某个有限时期内，地球一定曾经不适宜人类居住，而且在未来的某个有限时期内，地球也一定再次不适宜人类居住。”

The implication, he realized, was that the world had once been extremely hot and would inevitably become colder: “Within a finite period of time past the earth must have been, and within a finite period of time to come the earth must again be, unfit for the habitation of man.”

宇宙也是如此。它起源于一场大爆炸，此后便一路走下坡路。这一切都源于人们试图理解蒸汽机。

The same was true for the universe. It began with a bang and it has been downhill ever since. All that from trying to understand steam engines.

第八章

CHAPTER 8

AA·米歇尔森

A. A. Michelson

迷失太空

Lost in Space

阿尔伯特·A·米歇尔森

Albert A. Michelson

宇宙中没有地标；宇宙的每一部分都完全相同，因此我们无法确定自己的位置。我们仿佛置身于一片平静的大海，没有星辰、罗盘、测深仪、风向或潮汐，也无法辨别方向。我们没有航海日志可以用来推算航位；我们可以计算出相对于周围天体的运动速度，但我们并不知道这些天体在宇宙中的运动状态。

There are no landmarks in space; one portion of space is exactly like every other portion, so that we cannot tell where we are. We are, as it were, on an unruffled sea, without stars, compass, soundings, wind, or tide, and we cannot tell in what direction we are going. We have no log which we can cast out to take a dead reckoning by; we may compute our rate of motion with respect to the neighboring bodies, but we do not know how these bodies may be moving in space.

——詹姆斯·克拉克·麦克斯韦，《事项与动议》

—James Clerk Maxwell, Matter and Motion

对于像阿尔伯特·亚伯拉罕·迈克尔逊这样的老水手来说，麦克斯韦所描述的景象简直是一场噩梦——在无风的夜晚漂泊，没有一颗星星指引方向。迈克尔逊年轻时在美国海军服役，在安纳波利斯海军学院和海上实践航海，学习物理学。你必须忘掉哥白尼，像托勒密那样思考。你和你的船位于宇宙的中心，以环绕的星辰为指引。在确定自身位置时，你会考虑船速，并根据风速和风向进行调整。但即便像他这样年轻的少尉感到迷茫困惑，他也知道他的船正处于某种神圣之眼的十字准星之下——精确地位于某个特定的经纬度。当我们航行于宇宙时，情况肯定也是如此。一定存在某种标准，某种固定的衡量依据。

FOR AN old sailor like Albert Abraham Michelson, what Maxwell was describing was a nightmare—to be adrift on a windless night without a star to guide you. Michelson had learned his physics as a young man in the U.S. Navy, both at the Academy in Annapolis and on the ocean, practicing the art of navigation. You had to forget Copernicus, think like Ptolemy. You and your ship were at the center with the orbiting stars as your guide. In reckoning your position, you would take into account the velocity of your vessel, adjusting for the speed and direction of the wind. But as lost and confused as a young ensign might feel, he knew that his ship was in the crosshairs of some godly eye—precisely at a certain latitude and longitude. Surely the same must be true as we sailed the universe. There had to be some kind of standard, something fixed to measure by.

他当时是这么希望的。那是1885年，过去几周，米歇尔森一直心神不宁，住在纽约市的诺曼底酒店，接受一位著名精神病学家的治疗。正如他的合作者爱德华·莫利所说，他精神恍惚——一会儿激情澎湃，一会儿又抑郁寡欢。他的妻子试图把他送进精神病院。他的孩子们都害怕他。医生最终认定他并没有什么危险的疾病。但米歇尔森显然是一个痴迷于光和色彩的人，痴迷于光束碰撞如何使昆虫翅膀闪烁出虹彩般的光芒。他设想了一种光影交错的音乐，演奏者坐在键盘前，弹奏光谱中的视觉音符、色彩和弦和琶音，“展现人类心灵的所有幻想、情绪和情感”。

Or so he hoped. It was 1885 and for the past several weeks, Michelson himself had been unmoored, living at the Hotel Normandie in New York City under the care of a prominent psychiatrist. He’d gone soft in the head, as his collaborator Edward Morley put it—driven one moment, depressed the next. His wife tried to commit him to an asylum. His children were scared of him. The doctor ultimately decided that there was nothing dangerously wrong. But Michelson was clearly a man obsessed—by light and by color, by the way colliding beams caused the iridescent shimmer of an insect’s wings. He imagined luminescent music, where the performer would sit at a keyboard and play visual notes from the spectrum, color chords and arpeggios, “rendering all the fancies, moods, and emotions of the human mind.”

1885年11月，迈克尔逊心急如焚地准备返回位于克利夫兰凯斯应用科学学院的实验室，却发现他的职位已被他人取代，而且他还得接受降薪。尽管如此，他还是回到了家，搬进了那间让他感到不再受欢迎的房子后屋，开始筹备他最伟大的实验——利用光束测量地球在太空背景下的运行速度。

In November 1885, Michelson, in a manic mode, prepared to return to his laboratory at the Case School of Applied Science in Cleveland, only to find that his position had been filled and that he would have to take a salary cut. He came home anyway, moved into the back room of a house where he no longer felt wanted, and prepared for his greatest experiment—using light beams to clock the velocity of the Earth against the backdrop of outer space.

在《两种新科学》中，伽利略提出了一种检验光是瞬时还是以有限速度传播的方法。实验者在夜晚站在山顶上，向远处的山丘发射一道强光，远处的助手等待信号，并用强光回应。如果没有明显的延迟，就可以得出结论：“即使光不是瞬时的，它的速度也非常快。”

IN Two New Sciences, Galileo had suggested how one might test whether light is instantaneous or moves with a finite speed. Standing on a hilltop at night, an experimenter would flash a bright light toward a distant hill, where an assistant, awaiting the signal, would answer by flashing back. If there was no noticeable delay, one could conclude that “if not instantaneous, light is very swift.”

地球上没有任何山丘远到足以让我们真正分辨光速，但在17世纪70年代，丹麦天文学家奥勒·罗默找到了一种方法，可以测量整个太阳系的光速。他在一年中的某些时候用望远镜观测木星，发现木星最内侧的卫星木卫一（伊奥）的轨道速度似乎在减慢。罗默推测，这是因为随着木星及其卫星距离地球越来越远，它们的光线到达地球所需的时间也越来越长。结合当时已知的行星距离，他的观测结果表明光速约为每秒22.5万公里（14万英里）。

No hills on earth are far enough to really tell, but in the 1670s the Danish astronomer Ole Roemer found a way to make the measurement across the solar system. Training his telescope on Jupiter at certain times of the year, he noticed that its innermost moon, Io, seemed to be slowing in its orbit. That, Roemer surmised, was because as Jupiter and its moons moved farther from Earth, their light took longer to reach us. Taking into account what was known about planetary distances, his observations implied a light speed of about 225,000 kilometers (140,000 miles) per second.

这是一个大胆的结论——开普勒和笛卡尔都确信光速无限大——直到半个世纪后，英国天文学家詹姆斯·布拉德利发现了一种名为星光光行差的现象，才证实了这一结论。他追踪天龙座γ星，发现它偏离了预期的位置，从9月到次年3月持续向南移动，然后又向北移动。在排除了其他可能性之后，他找到了答案：当星光到达他的望远镜时，地球的位置已经发生了变化。就像猎鸭人需要用步枪瞄准一样，天文学家也必须用望远镜来“瞄准”。根据布拉德利的数据，光速为每秒18.3万英里。

It was a bold conclusion—Kepler and Descartes had been sure that light moved infinitely fast—that was not confirmed until half a century later when an English astronomer, James Bradley, discovered a phenomenon called the aberration of starlight. Tracking the star Gamma Draconis, he found that it wandered from its expected position, moving steadily southward from September to March and then northward again. After ruling out other possibilities, he hit on the explanation: by the time the starlight reached his telescope, the Earth had shifted position. Like a duck hunter leading with his rifle, an astronomer had to lead with his telescope. Based on Bradley’s data, light traveled at 183,000 miles per second.

罗默绘制的示意图，展示了从地球绕太阳轨道上的不同位置观测到的木星（B）遮蔽其卫星木卫一（DC）的现象。

A diagram by Roemer of Jupiter (B) eclipsing its moon Io (DC) as viewed from different points in the Earth’s orbit around the sun

1849年，法国物理学家阿曼德-伊波利特-路易·菲佐利用伽利略闪光灯的改进版，进行了更为直接的测量。他从巴黎西郊的一所房子里，向蒙马特高地上的一面镜子投射一束光，镜子将光反射回来。在光路中，有一个高速旋转的齿轮，齿轮上有720个精密加工的齿。当齿轮的转速设定得恰到好处时，光线（包括入射光和入射光）会穿过齿轮圆周上的一个缝隙，并在菲佐的目镜中呈现出“像星星一样的发光点”。如果齿轮的转速稍快或稍慢，光束就会被遮挡。菲佐根据光路的长度和齿轮的转速，估算出光速约为每秒196,000英里（315,400公里）。

In 1849 the French physicist Armand-Hippolyte-Louis Fizeau made a more direct measurement with a sophisticated version of Galileo’s flashing lanterns. From a house in the western suburbs of Paris he projected a light beam toward a mirror atop Montmartre, which reflected it back again. Interposed in the path was a rapidly spinning cogwheel with 720 precisely machined teeth. When the rotational speed was set just so, the light, going and coming, would pass through a gap in the wheel’s circumference and appear in Fizeau’s eyepiece as “a luminous point like a star.” Spin the wheel a little faster or slower and the beam would be eclipsed. From the length of the light path and the speed of the wheel, Fizeau estimated the velocity of light at about 196,000 miles (315,400 kilometers) per second.

菲佐实验。光线被投射到快速旋转的齿轮的齿间，照射到镜子（M）上，镜子又将光线反射回齿轮。

The Fizeau experiment. Light is projected between the teeth of a rapidly spinning cogwheel onto a mirror (M), which sends it back through the wheel again.

十三年后，他的竞争对手莱昂·傅科改进了这项实验，用一面倾斜旋转的镜子代替了齿轮。光线在两次传播过程中，会分别在镜子旋转的不同位置照射到镜子上。通过测量这种微小的位移，人们得出光速为每秒185,000英里（297,700公里）。

Thirteen years later, his rival Léon Foucault refined the experiment, replacing the cogwheel with a spinning mirror set at an angle. On the two legs of its journey, the ray would strike the mirror at slightly different points in its rotation. Measuring the tiny displacement gave light speed as 185,000 miles (297,700 kilometers) per second.

傅科实验。光源（S）发出的光线掠过旋转镜（R），然后穿过透镜（L）到达第二面镜（M）。当光束返回时，第一面镜已经移动，导致光束发生轻微偏转。

The Foucault experiment. Light from the source (S) glances off the spinning mirror (R), then travels through the lens (L) to a second mirror (M). By the time the beam returns, the first mirror has moved, causing a slight deflection.

米歇尔森很可能是在安纳波利斯海军学院学到了这一切。1869年，他辗转来到这所学院。作为波兰移民的长子，他随家人迁居加利福尼亚，父亲在金矿营地开了一家杂货店。后来，他们追逐着淘银热潮来到内华达州。高中毕业后，阿尔伯特申请了海军学院。由于未能从国会议员那里获得入学资格，他竟大胆地乘火车前往华盛顿，并说服尤利西斯·S·格兰特总统出面干预。到1874年，米歇尔森已是“伍斯特”号军舰上的少尉，后来在安纳波利斯担任物理和化学讲师。正是在那里，他遇到了玛格丽特·海明威，她是物理系主任的侄女，也是一位华尔街大亨的女儿。他们于 1877 年结婚，一年后，米歇尔森用岳父提供的 2000 美元开始计划他的第一个大型实验。

Michelson would have learned all this at the Naval Academy in Annapolis, where he had arrived in 1869 by his own circuitous route. The oldest son of Polish immigrants, he had moved with his family to California where his father opened a dry goods store at a gold mining camp. Later they followed the silver rush to Nevada, and after high school Albert applied to the Academy. When he failed to get an appointment from his congressman, he had the temerity to catch a train to Washington and persuade President Ulysses S. Grant to intervene. By 1874 Michelson was an ensign aboard the USS Worcester, going on to become an instructor in physics and chemistry at Annapolis. It was there that he met Margaret Heminway, the niece of an officer who headed the physics department and the daughter of a Wall Street tycoon. They married in 1877, and a year later, with $2,000 from his father-in-law, Michelson began planning his first big experiment.

在傅科尝试用旋转镜测量光束时，光束从旋转镜面反射的位移小于一毫米——这非常难以测量。迈克尔逊知道，如果他能将光束投射到更长的路径上（傅科的路径只有二十米长），滞后时间就会大大增加。返回的光束会在其周期的更晚阶段撞击镜面，从而产生更大的偏转，他希望这样就能更准确地测量光速。

In Foucault’s attempt to clock a light beam, the displacement from the spinning mirror was less than a single millimeter—very difficult to gauge. Michelson knew that if he could project the beam down a much longer path (Foucault’s was just twenty meters long), the lag time would be that much greater. The returning beam would hit the mirror later in its cycle, resulting in a larger deflection and, he hoped, a better value for the speed of light.

米歇尔逊绘制的旋转镜图

Michelson’s drawing of his rotating mirror

他首先在校园北侧海堤上放置了两面镜子，一面旋转，一面固定，两面镜子相距约2000英尺。为了精确测量两面镜子之间的距离，他使用了一根钢卷尺，并用“标准码”的复制品进行了校准。他用铅块将钢卷尺沿码头平放，并仔细确保其保持恒定的张力，然后进行了多次读数。考虑到温度对钢卷尺热胀冷缩的影响，最终得出两面镜子之间的距离为1986.23英尺。

He began by placing two mirrors, one revolving and one stationary, about 2,000 feet apart along the north seawall of the campus. To measure the separation precisely, he used a steel tape, calibrated against a copy of the “standard yard.” Holding the tape flat along the pier with lead weights, and taking pains to ensure that it was stretched at a constant tension, he made several readings. Correcting for the effect of temperature on expansion and contraction of the tape, the distance between the mirrors came out to be 1,986.23 feet.

一切都必须精准无误。为了调整固定镜的位置——这面镜会将光束反射回长路径——他使用了望远镜和一种名为经纬仪的测量设备。为了测量旋转镜的转速，他使用了一个电动音叉（他已将其与标准音叉进行了精确校准）。一个小钢镜被安装在音叉的一个叉齿上，反射着旋转装置的影像。当振动频率与旋转速度一致时，影像就会以频闪的方式定格。

Everything had to be just so. To adjust the position of the stationary mirror, the one that would bounce the light beam back down the long course, he used a telescope and a surveying device called a theodolite. To clock the speed of the revolving mirror he used an electric tuning fork (which he had meticulously calibrated against a standard tuning fork). A small steel mirror was attached to one of the tines, reflecting an image of the spinning apparatus. When the frequency of vibration coincided with the speed of rotation, the image would freeze stroboscopically.

他利用蒸汽动力鼓风机使镜子以每秒256转的速度旋转，并通过透镜聚焦阳光，测量出光线在旅程末端的偏转量为133毫米——“大约是傅科测量结果的200倍”。经过一番计算，他得出光速为每秒299,940公里或186,380英里——略高于如今公认的186,282.397英里。（科学家们对这个数字如此确信，以至于现在米的定义是基于光速，而不是反过来。）

Using a steam-powered blower to spin the mirror at 256 revolutions per second and sunlight focused through a lens, he measured the deflection at the end of the light’s journey at 133 millimeters—“being about 200 times that obtained by Foucault.” A few calculations yielded a speed of 299,940 kilometers or 186,380 miles per second—just slightly higher than today’s accepted value of 186,282.397. (So confident are scientists of that number that the meter is now defined in terms of the speed of light rather than vice versa.)

《纽约时报》评论道：“看来美国科学界注定要迎来一个崭新而辉煌的名字” ，并预测光的测量“将几乎与普通抛射体的速度一样精确”。

“It would seem that the scientific world of America is destined to be adorned with a new and brilliant name,” the New York Times observed, predicting that light would soon be measured “with almost as much accuracy as the velocity of an ordinary projectile.”

当迈克尔逊用他的光学测速仪崭露头角时，科学家们认为他们已经解决了光是由粒子还是波构成的这个问题。牛顿曾将光想象成“球状体”，甚至试图用这种方式解释折射现象。他认为，不同颜色的光粒子穿过棱镜后重新进入空气时，会获得不同的旋转，就像“用斜拍击打网球”一样。

BY THE time Michelson was making his mark with his optical speedometer, scientists thought they had settled the question of whether light was made of particles or waves. Newton had imagined light as “globular bodyes” and even tried to explain refraction that way. Passing through a prism and reentering the air, different-colored particles would be given different spins, like “a Tennis-ball struck with an oblique Racket.”

更难理解的是后来被称为牛顿环的现象，即当一块弯曲的玻璃和一块平坦的玻璃压在一起时，会出现明暗相间的条纹。牛顿勉强地提出，这些颜色是由光粒子经历“易反射和易透射”的过程造成的。

Harder to fathom was the phenomenon that came to be called Newton’s rings, the target of dark and light bands that appeared when a curved and a flat piece of glass were pressed together. Grasping at straws, Newton theorized that the colors were caused by light particles undergoing “fits of easy reflexion and transmission.”

直到1801年，托马斯·杨（在他著名的双缝干涉实验中）证明了两束重叠的光束可以相互干涉，产生相似的图案，才出现了更好的理论。杨提出，唯一能解释这种现象的方法是使用波。当两个波峰重叠时，会产生较亮的部分；当波峰相位不同时，会产生较暗的部分。在其他实验的验证之后，波动理论几乎被奉为圭臬，但它也留下了一个挥之不去的问题：究竟是什么在产生波动？

No better theory was established until 1801, when Thomas Young (in his famous two-slit experiment) showed how two overlapping light beams can interfere with each other, producing a similar pattern. The only way to explain this, Young proposed, was with waves. The lighter sections were produced when two wave crests overlapped, the darker sections when the crests were out of phase. After other confirming experiments, the wave theory came to be considered almost gospel, but it left a nagging question: What was doing the waving?

托马斯·杨的干涉图样

Thomas Young’s interference pattern

最终浮现的答案是另一个难以捉摸的事物：“发光以太”，一种弥漫万物——甚至原子间隙——的神秘存在。以太如同虚无般稀薄，据说它能够振动并传递光。更重要的是，它有望成为星际航行者噩梦的解药。在宇宙中漂流时，我们无法以邻近恒星为参照来确定自身的位置或速度，因为恒星也在运动。但一切都可以以以太为参照来衡量。

The answer that emerged was another of those imponderables: the “luminiferous aether,” an ineffable something that pervaded everything—even the spaces between atoms. As rarefied as nothingness itself, aether was said to have the ability to vibrate and transmit light. More fundamentally, it promised an antidote for the celestial sailor’s nightmare. Drifting through space, we cannot fix our position or velocity against the neighboring stars, for the stars are moving too. But everything could be measured against the aether.

1880年，在安纳波利斯著名的实验两年后，迈克尔逊从海军请了一年假前往欧洲学习。他和家人一起前往巴黎，玛格丽特当时正在那里读女子精修学校。在那里，他与法国物理学家们商讨一项测量地球相对于以太运动的计划。如果他的理论正确，那么一束沿地球绕太阳运动方向发射的光束应该会受到以太风的轻微影响而减速。要证明这一点，只需测量光在逆风和顺风方向上的速度，并比较两者即可。但这存在一个问题。为了观测到偏转，每束光束都必须像安纳波利斯实验那样从一面镜子反射回来。任何单向传播速度的变化都会在另一个方向上被抵消。（逆流而上再顺流而下所需的时间与顺流而下再逆流而上所需的时间相同。）

IN 1880, two years after his celebrated experiment at Annapolis, Michelson took a year’s leave from the navy to study in Europe. Traveling with his family to Paris, where Margaret had gone to finishing school, he conferred with French physicists about a plan to measure the motion of the Earth against the aether. If he was right, a light beam sent in the same direction that the Earth was moving around the sun should be slowed a little by an aether wind. Proving so would be a matter of measuring light speed upwind and downwind and comparing the two. But that posed a problem. Each beam would have to bounce off a mirror, as in the Annapolis experiment, in order for the deflection to be observed. Any change in velocity from traveling one way would be canceled out in the other direction. (Swimming upstream and then down takes the same amount of time as swimming downstream and then up.)

但他提出，如果将信标以直角发射出去，一个指向地球轨道方向，另一个横向发射，结果会怎样呢？正如迈克尔逊所说，现在，一名游泳者“逆流而上，奋力游回，而另一名游泳者游完同样的距离，只需横渡河流即可返回。如果河水有水流，第二名游泳者总是会赢。 ”

But what, he proposed, if the beacons were sent out at right angles, one in the direction of the Earth’s orbit and the other crossways? Now, as Michelson put it, one swimmer is “struggling upstream and back, while the other, covering the same distance, just crosses the river and returns. The second swimmer will always win, if there is any current in the river.”

或者，就光束而言，如果存在以太风的话。

Or in the case of the light beams, if there is an aether wind.

同年晚些时候，他前往柏林，开始组装他的仪器。手工制作的光学元件价格昂贵，但在一位国内同事的帮助下，迈克尔逊从亚历山大·格雷厄姆·贝尔那里获得了一笔资助。

Moving on to Berlin later that year, he began assembling his apparatus. The handmade optics were expensive, but with the help of a colleague back home, Michelson got a grant from Alexander Graham Bell.

实验中，灯笼发出的光会聚焦到一面半镀银的镜子上，镜子会将光束分成两束垂直方向的发光“光束”。这两束光束沿着两根长一米的精密加工黄铜臂传播，在镜子间反射后再次汇合。如果两束光束的传播速度不同，它们的相位就会略有偏差，波峰不会完全重合。

In the experiment, light from a lantern would be focused onto a half-silvered mirror, which would split the beam into two luminous “pencils,” running in perpendicular directions. Traveling along two finely machined brass arms, each a meter long, they would ricochet off mirrors and come back together again. If the beams had moved at different speeds they would be slightly out of phase, with the crests of their waves not quite lining up.

其结果将产生类似托马斯·杨所描述的干涉效应：明暗相间的线条图案，或称“条纹”。将仪器旋转九十度，改变其相对于以太之河的方向，条纹应该会移动。考虑到地球相对于以太的运动速度和光的波长，他预测至少会移动十分之一条纹，他确信自己能够测量到这一数值。

The result would be an interference effect like the one Thomas Young had described: a pattern of dark and bright lines, or “fringes.” Revolve the instrument ninety degrees, changing its orientation to the aethereal river, and the fringes should move. Taking into account the speed of the Earth against the aether and the wavelength of the light, he predicted a displacement of at least one-tenth of a fringe, something he was confident he could measure.

在如此精密的实验中，哪怕最轻微的震动都可能影响光程，从而破坏实验结果。（他后来写道：“这台仪器极其灵敏，以至于在距离天文台约100米的地方，哪怕只是跺脚，干涉条纹都会完全消失！”）为了保持干涉仪的稳定，他将其固定在一个石墩上。为了尽量减少温度差异（这可能会导致黄铜臂膨胀或收缩），他用纸盒盖住黄铜臂，甚至尝试用融化的冰块将仪器包围起来。然而，这些预防措施仍然不够。即使过了午夜，柏林的喧嚣也使得读数变得不可能。

In so delicate an experiment, the slightest vibration might throw off the path lengths and spoil the results. (“So extraordinarily sensitive was the instrument,” he later noted, “that the stamping of the pavement about 100 meters from the observatory, made the fringes disappear entirely!”) To keep the device—the interferometer—steady he anchored it to a stone pier. To minimize temperature differences, which might cause the brass arms to expand or contract, he covered them with paper boxes, and even tried surrounding the equipment with melting ice. The precautions were not enough. Even after midnight, the bustle of Berlin made it impossible to take a reading.

从顶部和侧面观察迈克尔逊的第一台干涉仪

Michelson’s first interferometer, viewed from the top and from the side

为了寻找更安静的环境，他搬到了波茨坦，并将设备安装在了天体物理天文台的地下室里。起初，当他旋转装置时，他以为看到了明显的条纹偏移。后来他意识到，自己只是无意中弯曲了黄铜臂。他重新制作了枢轴，使其转动更顺畅，然后再次尝试。

In search of quieter surroundings, he relocated to Potsdam and installed the equipment in the cellar of the Astrophysical Observatory. At first, as he rotated the device, he thought he saw a substantial fringe shift. Then he realized he was accidentally flexing the brass arms. He had the pivot remade to turn more freely and tried again.

他日复一日地测量，反复调整干涉仪的角度，却始终无法发现哪怕是最微小的偏移——条纹的百分之^一——如此微弱，他只能将其归咎于实验误差。此时已是四月初，地球正与整个太阳系朝着同一方向运动，其相对于以太的速度不断加快，然而似乎仍然没有产生任何显著的影响。1881年，他写信给他的资助人贝尔，报告了这一否定性的结果。迈克尔逊明确指出，这不应被视为否定以太的存在。以太必然存在。但或许，正如其他物理学家所提出的，背景并非完全固定。也许地球附近的某些以太正随着地球绕太阳的运行而被拖拽着。在飓风眼中，那里不会有风。迈克尔逊的信心坚定不移。 “我非常敬佩他的能力，”贝尔后来写道，“不过从他的举止来看，我倒觉得他自己也很敬佩我的能力。”

Day after day he measured, turning his interferometer this way and that, but he could find no more than the tiniest shift—¹/100 of a fringe—so slight that he could only dismiss it as experimental error. By now it was early April, when the Earth moved in the same direction as the whole solar system, increasing its speed against the aether, yet there still appeared to be no significant effect. Writing to his benefactor, Bell, in 1881, he reported the negative result. Michelson made clear that this shouldn’t be taken as disproving the existence of the aether. There had to be aether. But maybe, as other physicists had suggested, the backdrop wasn’t entirely fixed. Perhaps some of the aether in the vicinity of Earth was being dragged along in its journey around the sun. Traveling in the eye of a hurricane there would be no wind. Michelson’s confidence was unshakable. “I have a very high respect for his abilities,” Bell would later write, adding: “though I rather suspect from his manner that he has too.”

米歇尔森唯一的希望是，以太拖曳效应并未完全消除，天体背景中仍有足够多的部分保持静止，可以作为测量的参照物。早在本世纪初，法国科学家弗朗索瓦·阿拉戈就提出了这种可能性，他曾试图测量星光撞击地球的速度。阿拉戈很自然地假设，速度会随着行星远离光源而变化。他将一个棱镜安装在望远镜的末端，预测速度更快的光束会比速度更慢的光束发生更剧烈的弯曲。然而，他惊讶地发现，无论季节如何，弯曲角度都保持不变。

MICHELSON’S only hope was that the aether drag was not complete, that enough of the celestial backdrop stayed put to provide a landmark to measure by. This possibility had been suggested earlier in the century by a French scientist, François Arago, who had tried to measure the velocity of starlight colliding with the Earth. Arago assumed, naturally enough, that the speed would vary depending on whether the orbiting planet was approaching or retreating from the light source. He mounted a prism on the end of a telescope, predicting that faster light beams would be bent more abruptly than slower ones. He was surprised to find that whatever the season the angles were the same.

阿拉戈由此得出结论：我们的眼睛只能感知到很小范围的速度，速度过快或过慢的光线都是不可见的。但他的同事奥古斯丁-让·菲涅耳提出了不同的解释：虽然以太可以毫不费力地穿过物质的分子缝隙，但有一小部分以太却滞留在阿拉戈的棱镜中，随波逐流。菲涅耳解释说，这会抵消阿拉戈所寻求的效应。当地球接近一颗恒星时，地球的光线确实会以更高的速度照射到棱镜上。但随后，被困在棱镜内的以太会使光线减速，从而产生补偿性的速度变化。菲涅耳提出，这种效应适用于任何透明介质，并且取决于介质的折射率——折射率是衡量介质对光线减速和弯曲程度的指标。因此，以太阻力在水中会很明显，但在空气中则微不足道。

Arago concluded that our eyes must be sensitive to only a small range of velocities, that the faster and slower rays were invisible. But his colleague Augustin-Jean Fresnel came up with a different explanation: while aether flows effortlessly through matter’s molecular cracks, a tiny bit had become stuck in Arago’s prism, carried along for the ride. That, he explained, would negate the effect Arago was seeking. When the Earth was approaching a star, its light would indeed strike the prism at a higher speed. But then it would be slowed a compensating amount by the aether trapped inside the glass. The effect would be true for any transparent medium, Fresnel proposed, and would depend on its index of refraction—a measurement of how much it slows and bends light. Aether drag would thus be noticeable in water but insignificant in air.

1882年，在欧洲休假结束后，迈克尔逊离开海军，加入刚刚成立的克利夫兰凯斯应用科学学院任教。第一年，他测量了真空中的光速（几乎完全准确，为每秒186,320英里）。之后，他与在蒙特利尔火车旅途中结识的一位朋友一起，开始重新思考以太实验。

In 1882, after his sabbatical in Europe, Michelson left the navy and joined the faculty of the Case School of Applied Science in Cleveland, which had just opened its doors. During his first year, he measured the speed of light in a vacuum (almost dead-on at 186,320 miles per second). Then, with a man he had befriended on a train trip to Montreal, he began to rethink the aether experiment.

邻近的西储大学的化学家爱德华·莫利和迈克尔逊一样，都是一丝不苟的科学家。两人一致认为，除非能够首先证实菲涅耳的假设——即天体背景固定在空间中，只有少量以太被透明物体拖曳——否则再次尝试探测地球的绝对运动是毫无意义的。这种微弱的影响是可以校正的。他们改进了菲佐的实验，让水流经一个管环，并将一束光分成两束，使其中一支铅笔顺着水流方向运动，另一支铅笔逆着水流方向运动。最终，他们证实了水确实对铅笔产生了微弱的推拉作用。（顺便提一句：虽然他们当时将此视为以太拖曳假说的佐证，但现在这种现象被解释为狭义相对论效应。）

Edward Morley, a chemist at neighboring Western Reserve University, was as meticulous a scientist as Michelson. The two men agreed that it would be pointless to make another attempt to detect the Earth’s absolute motion unless they could first confirm Fresnel’s hypothesis—that the celestial backdrop is fixed in space with only pinches of aether dragged along by transparent objects. So slight an effect could be adjusted for. Improving on an experiment Fizeau had done, they pumped water through a loop of tubing and split a light beam so that one pencil moved with the current, the other against. They ultimately confirmed that there was indeed a small push and pull by the water. (Anachronistic aside: though they took this as confirmation of the aether drag hypothesis, the phenomenon is now explained as an effect of special relativity.)

正是在进行这项实验的过程中，迈克尔逊的精神崩溃了。原因不明。他和妻子的婚姻一直很糟糕。他觉得妻子在社交场合话太多，总是想抢风头。妻子厌倦了克利夫兰的生活，也受够了丈夫在实验室或其他地方熬夜。她抱怨丈夫挪用家庭账户里的钱去买科研设备。当迈克尔逊前往纽约接受治疗时，莫利怀疑他是否还能重返科学界。

It was in the midst of this experiment that Michelson fell apart. The reasons are obscure. He and his wife had been stuck in a bad marriage. He thought she talked too much at social gatherings, always trying to steal the show. She was bored with Cleveland, tired of her husband’s late nights at the lab, or wherever he was. She complained that he took money from the household account to buy scientific equipment. When Michelson left for New York to be treated, Morley doubted that he would ever return to science.

也许那只是一厢情愿的想法。（迈克尔逊对待莫利的态度和其他人一样恶劣。）不到两个月后，莫利就回到了实验室，准备继续实验。然而，又一次挫折发生了——1886年，一场大火烧毁了凯斯学院，迈克尔逊不得不将抢救出来的设备搬到西华盛顿大学。最终，到了第二年春天，两人准备进行他们希望能够最终确定的实验，正如莫利所说，是为了确定“光在各个方向上的速度是否相同”。和迈克尔逊一样，他也认为答案是否定的。

Maybe that was wishful thinking. (Michelson had been treating Morley as shabbily as anyone.) Less than two months later he was back in the laboratory, ready to resume the experiment. There was another setback—in 1886 a fire destroyed the Case School, and Michelson had to move what was salvaged to Western. Finally, the next spring, the two men were ready for what they hoped would be the definitive test, to determine, as Morley put it, “if light travels with the same velocity in all directions.” Like Michelson, he assumed the answer was no.

迈克尔逊-莫雷实验。下图显示了两束光束的路径，这两束光束通过在十六面镜子之间来回反射而延长。

The Michelson-Morley experiment. The lower diagram shows the paths of the two light beams, which were extended by bouncing them back and forth between sixteen mirrors.

这一次，为了防止干涉仪产生任何轻微的震动，实验人员采取了更加细致的缓冲措施。所有部件都安装在一块约五英尺见方、十四英寸厚的砂岩板上，这块砂岩板连接在一个甜甜圈形状的木制浮标上，浮标漂浮在一个盛有水银的铸铁槽中。水银槽本身则放置在砖砌平台上的混凝土底座上。四个金属镜分别位于四个角上，用于来回反射阿根灯发出的光线，从而将光程——一条随地球运动的光程和一条横向光程——增加到三十六英尺。一个木制罩子保护光学仪器免受空气的影响。在仔细测量并调整了镜子之间的距离之后——校准的精度之高，甚至需要使用每英寸100牙的螺丝——实验正式开始。

This time even more care was taken to cushion the interferometer against the slightest vibration. The pieces were mounted on a sandstone slab, about five feet square and fourteen inches thick, which was attached to a wooden buoy, shaped like a doughnut and floating in a cast-iron trough of mercury. The trough itself was set on a concrete bed atop a brick platform. Four metal mirrors were set at each corner to reflect the light from an Argand lamp back and forth, increasing the path lengths—the one going with the Earth and the one moving across—to thirty-six feet. A wooden cover protected the optical instruments from the air. After carefully measuring and adjusting the distances between the mirrors—a calibration so precise that it required a screw with 100 threads to the inch—they began the experiment.

迈克尔逊轻轻一推，干涉仪便开始缓慢转动，每六分钟转一圈，他则在一旁走动。他小心翼翼地避开观测镜，透过目镜观察干涉条纹，并在刻度盘周围的十六个观测点向莫利报出读数。7月8日至12日期间，他们分别在中午和傍晚进行了观测，并未发现显著差异。两位游泳运动员同时返回。

With a push of the hand, the interferometer was set slowly moving, one turn every six minutes, while Michelson walked alongside. Taking care to avoid touching the observing scope, he peered through the eyepiece at the interference fringes, calling out a reading to Morley at sixteen stations around the dial. Between July 8 and 12 they took observations both at noon and in the evening, and found no significant difference. The two swimmers returned at the same time.

他们原本打算在不同季节采集样本，以观察地球轨道运动是否会产生影响，但现在看来意义不大。菲涅尔的理论肯定错了：确实有大量的以太随地球一起运动，掩盖了菲涅尔效应。要测量地球的绝对运动，需要在高空，甚至可能在外太空进行测量。

They had intended to take samples during different seasons, to see if Earth’s orbital motion made a difference, but there seemed little point. Fresnel must be wrong: a substantial amount of aether was indeed being dragged along with the planet, obscuring the effect. Measuring the absolute motion of the Earth would require carrying out measurements high above ground, maybe even in outer space.

莫利和另一位同事戴顿·克拉伦斯·米勒继续使用光程更长的干涉仪寻找以太。米勒甚至声称在威尔逊山顶进行的实验中探测到了这种空气物质，但他显然受到了温度波动的影响。1930年，迈克尔逊在山上进行的实验再次证实了他最初的结果。

Morley and another colleague, Dayton Clarence Miller, continued to look for aether using interferometers with even longer light paths. Miller even claimed to have detected the airy stuff with an experiment atop Mount Wilson, but he was apparently fooled by temperature fluctuations. In 1930 Michelson’s own experiments on the mountain reconfirmed his original results.

这并非他所愿。那时他已再婚，组建了第二个家庭，并荣获诺贝尔奖。但他一直在寻求更深层次的依靠：以太，“现代科学最宏大的概括之一——我们甚至会忍不住说，即使它并非如此，它也应该是真的。”

It was not what he had wanted. By then he had remarried, sired a second family, and been honored with a Nobel Prize. But he had sought a deeper anchor: aether, “one of the grandest generalizations of modern science—of which we are tempted to say that it ought to be true even if it is not.”

一年后，也就是1931年，他去世了。就在几个月前，他刚刚结识了爱因斯坦。爱因斯坦的狭义相对论解释了迈克尔逊和莫雷那项精妙实验的真正意义：他们证明，与预期相反，空间乃至时间都不存在固定不变的背景。随着我们在宇宙中穿行，我们的测量标尺时而缩短，时而延长，我们的时钟时而走得更快——这一切都是为了维护唯一真正的标准。这个标准并非以太，而是光速。

He died a year later, in 1931, just months after meeting Einstein, whose special theory of relativity had explained the true significance of Michelson and Morley’s beautiful experiment: they had proved, contrary to their expectations, that there is no fixed backdrop of space, or even of time. As we move through the universe, our measuring sticks shrink and stretch, our clocks run slower and faster—all to preserve the one true standard. Not aether but the speed of light.

第九章

CHAPTER 9

伊万·巴甫洛夫

Ivan Pavlov

衡量不可衡量之物

Measuring the Immeasurable

伊万·巴甫洛夫

Ivan Pavlov

我们必须痛苦地承认，正因为狗拥有极高的智力，它作为人类最优秀的家养动物之一，却常常成为生理实验的受害者。在长期实验中，当动物术后恢复并接受长时间观察时，狗的作用是不可替代的。此外，狗的表现也极其令人感动。它几乎是实验的参与者，凭借其理解和配合，极大地促进了研究的成功。

We must painfully acknowledge that, precisely because of its great intellectual development, the best of man’s domesticated animals—the dog—most often becomes the victim of physiological experiments. During chronic experiments, when the animal, having recovered from its operation, is under lengthy observation, the dog is irreplaceable. Moreover, it is extremely touching. It is almost a participant in the experiments conducted upon it, greatly facilitating the success of the research by its understanding and compliance.

——伊万·巴甫洛夫

—Ivan Pavlov

听他说话，你会以为这些动物都是志愿者，它们被招募来参与那项最终使伊万·彼得罗维奇·巴甫洛夫名扬天下的研究。拉达、莱斯卡和朱奇卡都是常见的犬类名字。还有佩斯特里（斑点）、拉斯卡（黄鼠狼）、索科尔（猎鹰）、齐甘（吉普赛人）、雷扎伊亚（红发女郎）、普德尔（贵宾犬）和沃龙（乌鸦）。还有小丑阿利金、美女克拉萨维茨、淑女利亚迪、快手波斯特雷尔、小偷兹洛代和老俄罗斯王子罗格迪。有的狗名叫贝加尔（以西伯利亚的一个湖泊命名）和成吉思汗。而最开始，有一只据说是巴甫洛夫最喜欢的狗，是一只塞特犬和柯利犬的混血，他给它取名叫德鲁佐克，意思是伙伴或小朋友。

TO HEAR him talk, you would have thought they were volunteers, these animals recruited for the research that would make Ivan Petrovich Pavlov a famous man. Lada, Lyska, and Zhuchka had common canine names. There were Pestryi (Spot), Laska (Weasel), Sokol (Falcon), Tsygan (Gypsy), Ryzhaia (Redhead), Pudel (Poodle), and Voron (Crow). There were Arleekin the Clown, Krasavietz the Beauty, Lyadi the Lady, Postrel the Fast One, Zloday the Thief, and Rogdi the Old Russian Prince. There were dogs named Baikal (after a Siberian lake) and Genghis Khan. And at the very beginning there was the one said to be Pavlov’s favorite, a setter-collie mix he called Druzhok, for Buddy or Little Friend.

与其他生理实验室中仍采用“急性”实验的动物相比，他们的处境要好得多。“急性”实验是指切开并杀死活体动物，观察其解剖结构的变化。在巴甫洛夫看来，这就像用木槌砸手表来观察它的运行规律一样荒谬。从他对哺乳动物消化系统的开创性研究开始（这项研究至今仍是胃肠病学的核心），他倾向于采用“慢性”实验方法：在麻醉状态下，对狗的胃、食道或唾液腺进行手术，以便收集和分析体液。巴甫洛夫被誉为欧洲最杰出的外科医生之一，他的手术环境比许多医院的消毒条件还要好。只有当动物完全康复后，才会开始长达数月甚至数年的观察。

They had it better than animals in other physiology labs that still employed the “acute” experiment: cutting open and sacrificing a living animal to observe the anatomical ticking. To Pavlov this was like smashing a watch with a mallet to see how it ran. Beginning with his pioneering studies of the mammalian digestive system, still at the core of gastroenterology, he favored the “chronic” approach: while the dog was under anesthesia, its stomach, esophagus, or salivary glands would be altered so fluids could be collected and analyzed. Pavlov became known as one of the most skilled surgeons in Europe, and he operated under antiseptic conditions better than those in many hospitals. Only when the animal had fully recovered would the observations, extending over months or years, begin.

到了20世纪初，当他的研究兴趣转向神经系统时，这种共生关系已臻于完美。作为食宿的回报，这些狗成为了实验对象，同时也是吉祥物。在实验室工作之余，它们会被带到研究所的院子里散步。有时，为了阐明生理学上的某个问题，巴甫洛夫会进行一些残酷的实验，但他对此却感到十分懊悔。“当我解剖并杀死一只活生生的动物时，我内心会发出痛苦的谴责，责备自己粗暴地摧毁了一个无与伦比的艺术机制。但我为了追求真理，为了造福人类，忍受着这一切。” 在那个动物被猎杀娱乐、被宰杀获取食物和皮革的世界里，他觉得自己为了追求知识而使用少量动物是正当的。

By the early 1900s, when his interest had turned to the nervous system, the symbiosis was complete. In return for room and board, the dogs became experimental subjects, and also mascots. Between sessions in the laboratory, they were taken for walks on the institute grounds. Sometimes to clarify a point of physiology, Pavlov resorted to acute experiments, but only with regret. “When I dissect and destroy a living animal, I hear within myself a bitter reproach that with rough and blundering hand I am crushing an incomparable artistic mechanism. But I endure this in the interest of truth, for the benefit of humanity.” In a world where animals were hunted for recreation and slaughtered for food and leather, he felt justified in using a few for the pursuit of knowledge.

这是人们通常对那些反对活体解剖的人给出的答案，这些人在当时的俄罗斯乃至如今的世界各地都存在。在他们看来，巴甫洛夫的实验一点也不美好。即使是对餐厅菜单上的鹅肝或实验室小鼠的命运毫不在意的狗主人，听到那些手术描述也会感到不适。令人欣慰的是，人们从中获得了知识。凭借严密的逻辑和精妙的设计，巴甫洛夫的狗实验打开了一扇通往遥远世界的大门，那个世界曾如同最遥远的星辰般遥不可及：大脑内部。

It was the usual answer one gave to the antivivisectionists, who were a part of the scene in Russia, as they are throughout the world today. From their perspective Pavlov’s experiments were anything but beautiful. Even a dog owner unperturbed by foie gras on a restaurant menu or the fate of a laboratory mouse might wince at the surgical descriptions. The consolation is the knowledge that was gained. With its crisp logic and elegant design, the work with Pavlov’s dogs opened a passage to a world that had seemed as remote as the farthest star: the inside of the brain.

他原本打算像父亲一样，成为俄罗斯东正教的一名神父。后来，他发现了达尔文。那是19世纪60年代末，伊万和他的弟弟德米特里在梁赞的神学院学习，巴甫洛夫一家就住在那里。据说，每天清晨，伊万都会偷偷溜进村里的图书馆，阅读新近出版的俄文版《物种起源》 ，以及乔治·亨利·刘易斯的《人类生理学》（书中配有类似地图的内脏器官图解），还有伊万·谢切诺夫的《大脑的反射》，这是一部激进的纯粹唯物主义著作，认为人的思维只不过是一台极其复杂的机器。

HE HAD intended to become a priest, like his father, in the Russian Orthodox church. Then he discovered Darwin. It was the late 1860s, and Ivan and his brother, Dmitry, were studying at the seminary in Ryazan, where the Pavlovs lived. Early in the morning, the story goes, Ivan would sneak into the village library to read the recent Russian translation of On the Origin of Species as well as George Henry Lewes’s Physiology of Common Life, with its maplike diagrams of internal organs, and Ivan Sechenov’s Reflexes of the Brain, a radical exercise in pure materialism arguing that the mind was nothing more than an exceedingly complex machine.

谢切诺夫提出，从打喷嚏到决定阅读一本书，所有人类行为都由反射构成——即由感官接收到的信号触发的肌肉运动。他写道：“所有被描述为生动、激情、嘲讽、悲伤、喜悦等等的大脑活动外在表现，都仅仅是特定肌肉群收缩程度不同所致，而众所周知，这是一种纯粹的机械行为。”他坚持认为，即使一个想法不期而至，也是反射的产物，是微妙的环境线索唤起埋藏的记忆的结果。谢切诺夫宣称：“终有一天，人们能够像物理学家分析和弦或自由落体现象一样，轻松地分析大脑功能的外在表现。”

Sechenov proposed that every human behavior, from a sneeze to a decision to read a book, consists of reflexes—muscular movements triggered by signals registered by the senses. “Absolutely all the properties of the external manifestations of brain activity described as animation, passion, mockery, sorrow, joy, etc., are merely results of a greater or lesser contraction of definite groups of muscles,” he wrote, “which, as everyone knows, is a purely mechanical act.” Even when a thought pops into the head unbidden, it is the product of a reflex, he insisted, the evoking of a buried memory by subtle environmental cues. “The time will come,” Sechenov declared, “when men will be able to analyze the external manifestations of the functioning of the brain as easily as the physicist analyzes now a musical chord or the phenomena of a freely falling body.”

对于一位神父的儿子来说，这些想法令人振奋。在沙皇亚历山大二世统治时期，启蒙思想的曙光正笼罩着俄罗斯草原。在他父亲尼古拉一世统治时期会被禁的书籍和期刊纷纷涌入图书馆，图书馆门口总是挤满了人，他们推搡拥挤，争先恐后地想要挤进去。为了避开拥挤，巴甫洛夫有时会安排工作人员把窗户打开。

These were invigorating ideas for the son of a priest. Under the reign of Czar Alexander II, a penumbra of enlightenment was crossing the Russian steppes. Books and journals that would have been banned under his father, Nicholas I, were arriving at the library, where a crowd gathered at the doors waiting for them to open, pushing and shoving to get in. To beat the rush Pavlov would sometimes arrange for a worker to leave a window open.

他着迷于动物有机体可以用科学方法理解这一理念，于1870年离开神学院前往圣彼得堡深造。不久，德米特里也来到圣彼得堡，两人都在门捷列夫门下学习化学，当时门捷列夫正在设计元素周期表。然而，伊万专注于生理学，最终凭借对犬类神经系统如何控制血压和心脏泵血的实验研究，获得了医学博士学位。1891年，他被任命为新成立的实验医学研究所的生理学主任，在那里，他运用自己的外科手术技巧，绘制出了食物在体内加工和吸收的一系列功能——他称之为“复杂的化学工厂”。

Fascinated by the notion that the animal organism could be understood scientifically, he left the seminary in 1870 to study in Saint Petersburg. Dmitry soon joined him, and they both studied chemistry under Mendeleyev, who was devising his periodic table of the elements. Ivan, however, concentrated on physiology, eventually earning a doctorate of medicine for experiments on how the canine nervous system controlled blood pressure and the pumping of the heart. In 1891 he was appointed head of physiology at the newly formed Institute for Experimental Medicine, where he used his surgical techniques to map out the cascade of functions—a “complex chemical factory,” he called it—through which food was processed and absorbed by the body.

食物还没放到狗舌头上，唾液就开始分泌了：唾液中含有稀释食物的水分和润滑食物的黏液，以便食物顺利进入胃部。在胃里，胃液已经开始分泌，准备消化食物。在胃部以及之后的十二指肠中，特殊的神经感受器会分析食物，发出信号，让身体分泌适量的胃液，帮助消化面包、牛奶、肉类或其他任何狗晚餐吃的食物。

Even before a morsel was placed on a dog’s tongue, the flow of saliva began: water for dilution mixed with mucin to lubricate the food for its passage to the stomach, where a batch of “appetite juice” was already being prepared. There and later in the duodenum, specialized nervous sensors analyzed the food, signaling the body to secrete the proper recipe of gastric fluids needed to digest bread, milk, meat, or whatever the dog was having for dinner.

巴甫洛夫注意到，唾液分泌还有另一个作用。即使给动物尝到一些难闻的东西——比如芥末油、弱酸或盐——唾液仍然会分泌。但此时唾液的主要成分是水，用来保护舌头并冲走有害物质。在这种情况下，并没有胃液分泌。动物似乎“知道”胃液是不必要的。

Salivation, Pavlov noticed, also served another function. Give the animal a taste of something unsavory—mustard oil, mild acid, or salt—and saliva still flowed. But it consisted mostly of water to protect the tongue and wash out the noxious substance. In this case there were no gastric secretions. The organism somehow “knew” they were unnecessary.

为了测量唾液的量和成分，巴甫洛夫给狗做了一个小手术。在麻醉状态下，他将连接其中一个唾液腺的导管开口移到下巴或脸颊外侧，并用几针缝合固定。切口愈合后，他收集并分析了流出的液体。他发现，石英卵石几乎不会引起任何唾液分泌，而沙子则会释放出水分，方便狗漱口。同样的生理学原理也表明，狗吃一块干面包时流出的口水比吃一块美味的肉时要多。每一种反射都经过进化的精细调整，使动物能够更好地适应环境。

To measure the amount and the composition of the saliva, Pavlov subjected the dogs to a minor operation. While the animal was anesthetized, the opening of the duct leading from one of the salivary glands was moved to the outside of the chin or cheek and secured with a few stitches. Once the incision had healed, fluid was collected and analyzed. Pebbles of quartz, he found, produced hardly a drop, while sand released water so the dog could wash it out. By the same physio-logic, a dog actually drooled more at a piece of dry bread than a savory chunk of meat. Each reflex was fine-tuned by evolution to synchronize the animal with its environment.

实验医学研究所的场景

Scenes from the Institute of Experimental Medicine

他后来写道：“任何物质系统只有当其内部力、吸引力、内聚力等与作用于其上的外部力达到平衡时，才能作为一个实体存在。这对于普通的石头和最复杂的化学物质都适用，这一真理也应适用于动物有机体……反射是永恒平衡机制的基本单元。”

“Every material system can exist as an entity only so long as its internal forces, attraction, cohesion, etc., balance the external forces acting upon it,” he later wrote. “This is true for an ordinary stone just as much as for the most complex chemical substances, and its truth should be recognized also for the animal organism…. Reflexes are the elemental units in the mechanism of perpetual equilibration.”

1904年，巴甫洛夫因其在消化生理学方面的研究而荣获诺贝尔奖，但这一荣誉几乎与他失之交臂，因为一家竞争对手的实验室发现他遗漏了消化系统的一个重要组成部分：激素。“显然，我们并没有为发现真理申请独家专利，”他宿命般地说道。大约就在此时，他决定将消化系统的研究留给其他人，转而专注于他所谓的神经系统最高层部分。

In 1904 Pavlov won a Nobel Prize for his work on the physiology of digestion, an honor he was almost denied when a rival laboratory discovered that he had missed an important component of the system: hormones. “It is clear that we did not take out an exclusive patent for the discovery of truth,” he said fatalistically. It was around this time that he decided to leave digestion to others and concentrate on what he called the highest parts of the nervous system.

巴甫洛夫注意到，动物分泌唾液的现象，其实并不一定要食物进入它们的口中。食物的气味、碗的模样，甚至晚餐时门铰链的吱呀声，都足以引发这种反应。他称之为“精神分泌物”。

PAVLOV had noticed that for salivation to occur, it was not actually necessary for food to enter an animal’s mouth. The smell, the appearance of the bowl, even the creaking of a door hinge at dinnertime might be enough to set off the reaction. “Psychic secretions,” he called them.

与先天反射（即本能）不同，这些后天习得的或“条件反射”是可以改变的。给狗看一块肉，然后拿走。重复几次，狗的唾液分泌就会越来越少。这种反射被“抑制”了。尝一尝肉、面包，甚至，看似矛盾的是，尝一尝有害的酸，都能恢复（“解除抑制”）这种反应。正如漫长的进化使物种适应环境一样，一生的经验也使个体生物适应其特定环境的细节。它进化出了学习的能力。

Unlike the inborn reflexes—the instincts—these acquired or “conditional” responses could be modified. Show a dog a piece of meat and then take it away. Do this several times and the animal will salivate less and less. There has been an “inhibition” of the reflex. A taste of meat, bread, or even, paradoxically, noxious acid restores (“disinhibits”) the reaction. Just as evolution acting over eons molds a species to its environment, experience acting over a lifetime molds an individual organism to the details of its particular locale. It has evolved the ability to learn.

巴甫洛夫早期曾试图从心理学角度解释这些现象，想象狗的内心世界可能正在发生什么。这只狗在反复看到肉之后不再流口水，是因为它变得麻木、愤世嫉俗，仿佛“确信自己的努力毫无用处”。但为什么令人作呕的酸液又会让它重新分泌唾液呢？这只狗究竟在想什么？

Early on, Pavlov was tempted to interpret these phenomena psychologically, imagining what thoughts might be unfolding on the dog’s inner screen. The animal stopped drooling after repeated showings of meat because it had become jaded, cynical, as though “convinced of the uselessness of its efforts.” But why then would the revolting touch of acid bring salivation back? What could the dog be thinking?

巴甫洛夫后来认为，这个问题本身就是错误的。“我们究竟有什么方法可以进入动物的内心世界呢！”他后来宣称，“我们凭什么能够了解动物的感受？”他深刻地指出，同样的道理也适用于人类。“人生的永恒悲剧难道不就在于人与人之间无法相互理解，一个人无法进入另一个人的内心世界吗？”

This, Pavlov came to believe, was the wrong question. “Indeed, what means have we to enter into the inner world of the animal!” he later declared. “What facts give us the basis for speaking of what and how an animal feels?” The same, he poignantly observed, applies to people. “Does not the eternal sorrow of life consist in the fact that human beings cannot understand one another, that one person cannot enter into the internal state of another?”

精神与物质之间的界限开始变得模糊。巴甫洛夫指出，当科学家研究血压的升降或胰液的流动时，他完全是从物质层面进行论述。“但现在，生理学家转向中枢神经系统的高级部分，他的研究性质突然发生了剧烈的变化……他开始根据自身的主观感受来推测动物的内部状态。在此之前，他一直运用的是一般的科学概念。现在，他改变了方向，转而研究与他之前的概念毫无关联的陌生概念——心理学思想。简而言之，他从可测量的世界跃入了不可测量的世界。”

The line between the mental and the physical was beginning to blur. When a scientist studied how blood pressure rises and falls or pancreatic juices flow, Pavlov noted, he spoke in purely material terms. “But now the physiologist turns to the highest parts of the central nervous system, and suddenly the character of his research sharply changes…. Hebegins to make suppositions about the internal state of animals, based on his own subjective state. Up to this moment he had used general scientific conceptions. Now he changes front, and addresses himself to foreign conceptions in nowise related to his earlier ones, to psychological ideas. In short, he leaps from the measurable world to the immeasurable.”

是时候集中精力实现目标了。无论唾液腺是由舌头上的感受器，还是眼睛、鼻子或耳朵上的感受器刺激，结果都是一样的：来自环境的信号引发了生理反应。

It was time to concentrate on the objective. Whether the salivary glands were fired by receptors in the tongue or in the eye, nose, or ear, the result was the same: signals from the environment were eliciting a physiological reaction.

笛卡尔在十七世纪就提出了生物体（包括大脑）是生物机器的观点，但他承认人类具有某种特殊性。虽然我们的身体纯粹是机械的，受制于物理原理，但我们的大脑却栖息着一种更高层次的存在——心灵。到了巴甫洛夫的时代，达尔文的发现使得这种二元论难以维系。大脑或许与身体其他部分一同进化，但自然选择的物质力量又如何作用于虚幻的心灵呢？威廉·詹姆斯在1890年出版的《心理学原理》中描述了这个问题： “构成星云的那些原子，原本杂乱无章地分散着，如今却聚集在一起，暂时停留在奇特的位置，形成了我们的大脑；如果理解了大脑的‘进化’，那它就仅仅是对原子如何聚集在一起的解释。”

THE IDEA that organisms, their brains included, are biological machines was broached by Descartes in the seventeenth century, but he allowed that there was something special about his fellow humans. Although our bodies are purely mechanical, constrained to obey the principles of physics, our brains are inhabited by a higher presence, the mind. By Pavlov’s time, Darwin’s discoveries had made this kind of dualism tricky to maintain. The brain presumably evolved along with the rest of the body, but how could the material tugs of natural selection act on the ghostly mind? William James described the problem in 1890 in The Principles of Psychology: “The self-same atoms which, chaotically dispersed, made the nebula, now, jammed and temporarily caught in peculiar positions, form our brains; and the ‘evolution’ of the brains, if understood, would be simply the account of how the atoms came to be so caught and jammed.”

一些哲学家甚至提出，每一个物质原子都对应着一个意识原子——“原始心灵尘埃”，它们随着宇宙的展开和物种的进化而被带入其中。詹姆斯解释了他们的推理：“正如物质原子通过聚集形成身体和大脑一样，精神原子也通过类似的聚集过程融合为更大的意识。”

Some philosophers went so far as to propose that each atom of matter is shadowed by an atom of consciousness—“primordial mind-dust” that was carried along as the cosmos unfolded and species evolved. James explained their reasoning: “Just as the material atoms have formed bodies and brains by massing themselves together, so the mental atoms, by an analogous process of aggregation, have fused into those larger consciousnesses.”

婴儿逐渐形成对火的回避反射。图表来自威廉·詹姆斯，《心理学原理》。

A baby acquiring an avoidance reflex to fire. Diagram from William James, Principles of Psychology

大脑中的每一种化学活动都与一种心理活动平行进行，二者互不控制。托马斯·亨利·赫胥黎曾这样描述道：“灵魂与身体的关系，如同钟表的钟声与机械运转的关系，意识则回应着钟声敲响时发出的声音。”当我们“决定”移动手指时，这只是一个指示，而非事件的直接起因。赫胥黎提出：“我们称之为意志的感觉，并非自主行为的原因，而是大脑中导致该行为的直接原因所对应的状态的象征。”（一个世纪后，生理学家本杰明·利贝特声称已经证明了这一点。）

Running on a parallel track, every chemical action in the brain was said to be mirrored by a mental action, with neither exerting control over the other. Thomas Henry Huxley had put it like this: “The soul stands related to the body as the bell of a clock to the works, and consciousness answers to the sound which the bell gives out when it is struck.” When we “decide” to move a finger, that is an indication, not the instigator of the event. “The feeling we call volition,” Huxley proposed, “is not the cause of a voluntary act, but the symbol of that state of the brain which is the immediate cause of that act.” (A century later, the physiologist Benjamin Libet claimed to have demonstrated just that.)

换句话说，我们是有意识的自动机。詹姆斯不赞同地描述了这意味着什么：

We are, in other words, conscious automata. James disapprovingly described the implications:

如果我们彻底了解莎士比亚的神经系统，以及他所处的全部环境，我们就能解释为什么在他人生的某个阶段，他的手会在某些纸上留下那些潦草的小黑点，为了简洁起见，我们称之为《哈姆雷特》的手稿。我们就能理解其中每一次涂改和修改的缘由，而且这一切都无需丝毫承认莎士比亚脑海中存在任何思想。那些词句将被视为纯粹的、外在的事实，而非其本身所蕴含的任何其他意义。同样地，我们也能详尽地撰写马丁·路德——那大约两百磅重、略带温热的蛋白质——的传记，而无需暗示它有任何感觉。

If we knew thoroughly the nervous system of Shakespeare, and as thoroughly all his environing conditions, we should be able to show why at a certain period of his life his hand came to trace on certain sheets of paper those crabbed little black marks which we for shortness’ sake call the manuscript of Hamlet. We should understand the rationale of every erasure and alteration therein, and we should understand all this without in the slightest degree acknowledging the existence of the thoughts in Shakespeare’s mind. The words and sentences would be taken, not as signs of anything beyond themselves, but as little outward facts, pure and simple. In like manner we might exhaustively write the biography of those two hundred pounds, more or less, of warmish albuminoid matter called Martin Luther, without ever implying that it felt.

巴甫洛夫并没有在这些形而上学的问题上停留太久。无论狗的内心世界发生了什么，都只能从外部客观地去探究。“博物学家只需考虑一件事：动物的这种或那种外部反应与外部世界的现象之间有什么关系？”

Pavlov didn’t linger long on such metaphysical matters. Whatever might be happening inside a dog’s mind could be approached only from the outside, objectively. “The naturalist must consider only one thing: what is the relation of this or that external reaction of the animal to the phenomena of the external world?”

他很快意识到，这些信号与其所代表的事物本身并无必然联系。狗闻到肉味会流口水是自然而然的，但这似乎也是一种后天习得的反应。（一只还在吃母乳的小狗可能会对汉堡包不屑一顾。）但通过将肉与其他刺激同时呈现，实验者可以训练动物对闪光、物体旋转、冷热探针接触皮肤、节拍器的滴答声，或蜂鸣器、哨子、音叉或喇叭的声音产生唾液分泌的反应。（巴甫洛夫几乎从不使用铃铛。）进化论并没有理由预先想到这种任意的配对。但在当时的条件下，这些配对对狗的生存却具有了意义。

These signs, he was quick to learn, need bear no inherent relation to what they signify. It is natural that a dog’s mouth would water at the smell of meat, though that too seemed to be a learned response. (A puppy still imbibing its mother’s milk may turn up its nose at a hamburger.) But by presenting meat at the same time as another stimulus, the experimenter could train the animal to salivate at the flash of a light, the rotation of an object, the touch of a hot or cold probe to the skin, the ticking of a metronome, or the sound of a buzzer, whistle, tuning fork, or horn. (Pavlov hardly ever used a bell.) There is no reason evolution would anticipate such arbitrary pairings. But under the circumstances they became meaningful to the dog’s survival.

训练狗在两个机械刺激器刺破其皮肤时分泌唾液

Training a dog to salivate when two mechanical stimulators prick its skin

防御性唾液反应也是如此。狗一旦尝过用印度墨水染成黑色的稀释酸液，看到黑色的水就会分泌唾液以示保护。但几次尝过这种无害溶液后，这种反射就消失了，直到再次尝到酸液后才会恢复。

The same was true of the defensive salivary reaction. Once the dog had sampled dilute acid dyed black with India ink, it would drool protectively at the sight of black water. But after it had sampled the harmless solution several times, the reflex disappeared, only to be restored with another taste of the acid.

这些神经连接具有极强的可塑性，可以像电话交换机上的电缆一样随意插拔。经过足够的训练，像一块肉这样的积极刺激就可以与令人厌恶的刺激联系起来。例如，狗不会像以前那样对电击做出躲避反应，反而会流口水。

So malleable were the neural connections that they could be plugged and unplugged like cables in a telephone switchboard. With enough training, a positive stimulus like a piece of meat could be linked with an obnoxious one. Instead of recoiling at an electric shock the dog would drool.

随着巴甫洛夫技术的日臻完善，他的实验室开始研究犬类的时间感。在训练一只狗对闪光做出反应并分泌唾液后，刺激出现的时间被推迟了三分钟。不久之后，这只狗学会了预测这种延迟。信号出现三分钟后，它的口水就会分泌。

As his technique became more practiced, Pavlov’s laboratory began investigating the canine sense of time. After a dog was trained to salivate at a flash of light, the delivery of the stimulus was postponed by three minutes. Before long, the dog learned to anticipate the delay. Three minutes after the signal, the animal’s mouth would water.

在其他实验中，时间本身成了刺激物。每隔三十分钟给狗喂食。停止喂食后，它仍然会每隔半小时机械地分泌唾液。“我确信，”巴甫洛夫略带夸张地宣称，“沿着这条精确的实验之路，就能找到困扰了无数代哲学家的时间问题的答案。”

In other experiments time itself became the stimulus. Give a dog food every thirty minutes. When the feedings are suspended, it will continue to salivate robotically on the half hour. “I am convinced,” Pavlov declared, a bit grandiosely, “that directly along this path of exact experimentation lies the solution of the problem of time, which has occupied philosophers for countless generations.”

它们的神经机制非常精确，甚至可以训练狗来区分顺时针旋转的物体和逆时针旋转的物体，区分圆和椭圆，区分每分钟100次的节拍器和每分钟96次或104次的节拍器。它们可以区分音阶上相邻的音符，区分管风琴上五个不同八度音阶中演奏的C和F，以及不同的灰色色调。

So precise was their neural machinery that the dogs could even be conditioned to discriminate between an object rotating clockwise and one rotating counterclockwise, between a circle and an ellipse, between a metronome beating 100 times per minute versus 96 or 104. They could distinguish between adjacent notes on a musical scale, between C and F played in any of five different octaves on an organ, and among different shades of gray.

对于这类实验，实验环境至关重要。如果一只狗在地板上学会了一种新的反射动作，那么如果把它移到桌子上，或者由不同的实验人员重复实验，实验结果可能就会失败。因此，必须小心避免各种干扰因素。“路人的脚步声、隔壁房间的偶然谈话、关门声、过往货车的震动、街头叫喊声，甚至是透过窗户投射到房间里的影子，任何这些随意且不受控制的刺激都会影响狗的大脑半球，从而干扰实验结果。”

For experiments like this, the context was essential. If a dog learned a new reflex while it was sitting on the floor, the experiment might fail if it was repeated on a table, or by a different experimenter. Distractions had to be carefully avoided. “Footfalls of a passer-by, chance conversations in neighboring rooms, the slamming of a door or vibration from a passing van, street-cries, even shadows cast through the windows into the room, any of these casual uncontrolled stimuli falling upon the receptors of the dog set up a disturbance in the cerebral hemispheres and vitiate the experiments.”

巴甫洛夫的狗和迈克尔逊干涉仪一样性情多变。为了控制所有可能的变量，他委托建造了一座仿照地震实验室的“静音塔”。这座建筑四周环绕着一条装满稻草的护城河以减弱震动，其一楼和三楼各设有四个隔音观察室，这些观察室之间由走廊和空置楼层隔开。实验人员通过潜望镜远程观察狗，一位参观者形容这景象“就像一艘准备战斗的潜艇”。

Pavlov’s dogs were as temperamental as Michelson’s interferometer. Determined to control every possible variable, he commissioned the construction of a “Tower of Silence” modeled on seismological laboratories. The building was surrounded by a straw-filled moat to dampen vibrations, and its first and third floors each had four soundproof observation chambers isolated by corridors and the unoccupied floor in between. Experimenters observed the dogs remotely through periscopes, giving the impression, one visitor reported, of “a submarine ready for battle.”

正如历史学家丹尼尔·托德斯所称的“巴甫洛夫生理工厂”，它预示着实验科学未来的发展方向。在巴甫洛夫的指导下，研究团队用数百只不同的狗来检验各种假设。最终呈现的或许并非单一的精妙实验，而是一系列实验。然而，其中一项实验却格外引人注目，远超其他实验。

“Pavlov’s physiology factory,” as the historian Daniel Todes called it, was a sign of what experimental science would become. Under Pavlov’s direction teams of researchers tested hypotheses on hundreds of different dogs. What emerged was not, perhaps, a single beautiful experiment but a suite of them. Still, one was so surprising that it stands above the rest.

巴甫洛夫和他的合作者此前已经证明，狗具有基本的音乐能力。经过训练，狗会对特定的和弦（例如A小调）产生唾液分泌反应，它也会对每个单独的音符做出反应，尽管反应较弱。研究人员更进一步，开始测试狗识别简单旋律的能力。

Pavlov and his collaborators had already shown that a dog had basic musical abilities. Trained to salivate to a specific chord, say A-minor, it would also react—albeit more weakly—to each individual note. Pushing still further, the researchers began testing the animal’s ability to recognize simple melodies.

当奏出四个音符时，狗就得到了一点食物。

When four notes were played in ascension, the dog was given a bit of food.

当以降序演奏相同的音符时，没有出现增强效果。

When the same notes were played in descending order, there was no reinforcement.

这种动物很快就学会了区分不同的音序。但是巴甫洛夫想知道，当它听到相同音符的其他二十二种可能的组合时，它会作何反应呢？

The animal quickly learned to tell one sequence from the other. But how, Pavlov wondered, would it respond when it heard the twenty-two other possible combinations of the same notes?

旋律被播放，唾液被收集起来。这只狗根据音调的上升或下降趋势，将音阶分成了两个相等的组。可以说，这只动物已经形成了一个初步的概念。巴甫洛夫后来认为，这种模式识别正是他作为实验科学家所做工作的根源。

The melodies were played and the spittle collected. The dog had categorized the scales into two equal groups depending on whether the pitches were predominantly rising or falling. It’s not too much of a stretch to say that the animal had formed a rudimentary concept. This kind of pattern recognition, Pavlov came to believe, was the root of what he himself did as an experimental scientist.

“植物向光生长和通过数学分析寻求真理——这些现象难道不属于同一范畴吗？它们难道不是生物体中无处不在的、几乎无穷无尽的适应性链条中的最后环节吗？”

“The movement of plants toward the light and the seeking of truth through a mathematical analysis—are these not phenomena belonging to the same order? Are they not the last links in an almost endless chain of adaptabilities which appear everywhere in living creatures?”

像许多拥有强大理论的科学家一样，他有时也会得意忘形，试图用条件反射来解释狗的性格，甚至人类的神经症。在美国，约翰·B·华生和B·F·斯金纳发展了行为主义心理学，将一切心理活动简化为刺激和反应。由此产生了两种截然不同的未来愿景：斯金纳的小说《瓦尔登湖二》描绘了一个通过行为工程实现的乌托邦，而奥尔德斯·赫胥黎的《美丽新世界》则描绘了国家利用同样的工具建立残酷的独裁统治。然而，这两种愿景都未能实现。近年来，计算机的隐喻为科学家们提供了一种更为细致入微的思考思维的方式，但巴甫洛夫的基本认识却经久不衰：大脑和神经系统构成了一台精确且高度适应的活体机器。

Like many scientists with a powerful theory, he got carried away at times, trying to explain his dogs’ personalities and even human neurosis as bundles of conditional reflexes. In the United States, John B. Watson and B. F. Skinner developed the psychology of behaviorism, in which everything mental was reduced to stimuli and responses. The result was two clashing visions of the future: Skinner’s novel Walden Two describes a utopia brought on through behavioral engineering, while in Aldous Huxley’s Brave New World, the same tools are used by the state to impose a crushing dictatorship. Neither has come to pass. More recently the metaphor of the computer has given scientists a more nuanced way to think about thinking, but Pavlov’s fundamental realization has endured: the brain and nervous system form a precise, highly adaptable living machine.

巴甫洛夫晚年时，他的学生们送给他一本相册，里面有他四十只狗的照片。一位在冷泉港实验室工作的科学家在圣彼得堡找到了这本相册的副本。这位科学家当时正在果蝇身上进行巴甫洛夫条件反射实验，以识别与长期记忆相关的基因。他将这些果蝇的各种突变体命名为“巴甫洛夫果蝇”，以纪念这些著名的动物。

Later in his life Pavlov’s students gave him an album with photographs of forty of his dogs. A copy was tracked down in Saint Petersburg by a scientist at Cold Spring Harbor Laboratory who was using Pavlovian conditioning in fruit flies to identify genes involved in long-term memory. He named the various mutants—“Pavlov’s flies”—after the famous animals.

巴甫洛夫的狗

Pavlov’s dogs

狗的纪念碑

Monument to a Dog

1935年，研究所内建造了一座名为“狗纪念碑”的华丽喷泉。喷泉中心是一个基座，基座上坐着一只巨大的犬类，周围环绕着实验室场景的浅浮雕以及巴甫洛夫的名言：“让狗，这自史前时代以来人类的助手和朋友，为科学献身。但我们的道德尊严要求我们确保这一过程始终不会给它们带来不必要的痛苦。”

In 1935, Monument to a Dog, an ornate fountain, was built on the grounds of the institute. At the core is a pedestal with a large canine sitting on it with bas reliefs of laboratory scenes and quotations from Pavlov: “Let the dog, man’s helper and friend since prehistoric times, offer itself as a sacrifice to science. But our moral dignity obligates us to ensure that this always occurs without unnecessary pain.”

顶部周围是八只犬的半身像，它们口吐唾沫，敬礼时嘴里流出水来。

Around the top are busts of eight canines, water pouring from their mouths as they salute in salivation.

第十章

CHAPTER 10

罗伯特·密立根

Robert Millikan

在边境地带

In the Borderland

罗伯特·密立根

Robert Millikan

我们实际上已经触及了物质与力量似乎融为一体的边界地带，这片介于已知与未知之间的朦胧领域，对我而言，始终充满着一种奇特的诱惑。我大胆地认为，未来最伟大的科学难题将在这片边界地带，甚至更远的地方找到答案：在我看来，这里蕴藏着终极现实，微妙、深远、奇妙。

We have actually touched the borderland where matter and force seem to merge into one another, the shadowy realm between Known and Unknown which for me has always had peculiar temptations. I venture to think that the greatest scientific problems of the future will find their solution in this Border Land, and even beyond: here, it seems to me, lie Ultimate Realities, subtle, far-reaching, wonderful.

——威廉·克鲁克斯，1879年

—William Crookes, 1879

一月的一个星期六早上，为了找到最后一件能让我确信电子存在的设备，我前往了位于新墨西哥州洛斯阿拉莫斯的“黑洞”——一个宛如末日废品场的仓库（“所有东西都进去，却什么也出不来”）。这个仓库由爱德华·B·格罗瑟斯经营，他曾是一名炸弹制造者，如今是一位年迈的和平主义者。仓库由一家旧杂货店改造而成，从地板到天花板堆满了示波器、信号发生器、盖革计数器、真空泵、离心机、电流表、欧姆表、电压表、低温储存容器、工业炉、热电偶、气压计、变压器、打字机、老式机械计算器——超过一万七千平方英尺的电子和机械废料，这些都是曼哈顿计划的发源地——美国国家实验室多年来丢弃的。

ON A SATURDAY morning in January, in search of the last piece of equipment I needed to persuade myself that electrons exist, I set out for the “Black Hole,” a postapocalyptic junkyard (“Everything goes in and nothing comes out”) in Los Alamos, New Mexico. Run by Edward B. Grothus, a former bomb maker and now aging peace activist, the warehouse—converted from an old grocery store—is packed floor to ceiling with oscilloscopes, signal generators, Geiger counters, vacuum pumps, centrifuges, ammeters, ohmmeters, voltmeters, cryogenic storage vessels, industrial furnaces, thermocouples, barometric gauges, transformers, typewriters, ancient mechanical calculators—more than seventeen thousand square feet of electronic and mechanical detritus cast off over the years by the national laboratory where the Manhattan Project began.

多年来，我在eBay上搜罗了大部分重现经典实验所需的物品：1897年J·J·汤姆逊证明电是一种带负电荷的物质，十三年后罗伯特·密立根的辉煌油滴实验，分离并测量了单个电子的电荷。在“黑洞”商店昏暗的货架间穿梭，我终于找到了心仪之物：一台福禄克415B高压电源。我小心翼翼地从一堆机器中间取下这台长长的灰色机箱——它重达30磅——然后把它放到水泥地上。这台电源产于20世纪60年代，采用真空管驱动，看起来状态完美。我把它拖到商店后方，那里成排的同轴电缆像蛇一样挂在钩子上或盘绕在地上，我找到一根能匹配输出接口的电缆，然后走向收银台。

Over the years I had acquired on eBay most of what I’d need to repeat the classic experiments: J. J. Thomson’s 1897 demonstration that electricity is a form of negatively charged matter, followed thirteen years later by Robert Millikan’s triumphal oil-drop experiment, isolating and measuring the charge of individual electrons. Combing the dark aisles of the Black Hole, I finally spotted what I’d been looking for: a Fluke 415B High Voltage Power Supply. Reaching over my head, I carefully freed the long gray chassis from the middle of a stack—it weighed thirty pounds—and lowered it to the concrete floor. Built in the 1960s and operated by vacuum tubes, it appeared to be in perfect condition. Dragging it to the back of the store, where miles of coaxial cables hung snakelike from hooks or lay coiled on the floor, I found one that fit the output connector and made my way to the cash register.

埃德似乎从来都不想卖东西。他宁愿跟你吹嘘他打算在即将到来的大屠杀之后竖起两座花岗岩方尖碑，好让外星考古学家大吃一惊；或者吹嘘他的“高科技第一教堂”，他每周日都会在那里举行“临界质量”仪式。等一些顾客好不容易在他藏身的深处找到他时，他正闷闷不乐。“就这玩意儿要两百五十美元，”他说——差不多是我预期价格的十倍。我试图跟他讲道理。eBay 上有一个一模一样的，才卖 99 美元。但埃德可不是个会讨价还价的人。我失望地把那玩意儿拖回了它“安身之处”（估计现在还放在那里），只带走了那根电缆。我顺道去了公共图书馆，就在富勒小屋旁边，奥本海默和其他核物理学家以前常在那里聚会吃饭。我上网买了另一个电源。两周后，电源到了，一切准备就绪。

Ed never seems to actually want to sell anything. He’d rather tell you about his plan to erect a pair of granite obelisks to surprise alien archeologists after the coming holocaust, or about his First Church of High Technology, where he performs a “critical mass” on Sundays. By the time some customers tracked him down in the depths of his lair, he was in a cantankerous mood. “Two hundred fifty dollars for that,” he said—about ten times what I’d been expecting. I tried to reason with him. There was one exactly like it on eBay for $99. But Ed is not a man to bargain. Disappointed, I dragged the unit back to its resting place, where it is probably still sitting, and left with just the cable. Stopping at the public library, next to Fuller Lodge, where Oppenheimer and the other nuclear physicists partied and dined, I signed on to the Internet and bought the other power supply. Two weeks later it arrived and I was ready to begin.

1896年，刚从哥伦比亚大学获得博士学位的年轻物理学家罗伯特·安德鲁斯·密立根在柏林聆听了一场讲座，威廉·伦琴正在展示他拍摄的手部骨骼照片。当时正值德国物理学会一月份的会议，密立根感到无比惊奇，以至于后来他误以为讲座是在圣诞前夜举行的。

IN 1896, Robert Andrews Millikan, a young physicist fresh out of Columbia University with a PhD, found himself at a lecture in Berlin where Wilhelm Roentgen was showing pictures he had taken of the bones inside a hand. The occasion was a January meeting of the German Physical Society, and Millikan felt such childlike wonder that he later misremembered the talk as occurring on Christmas Eve.

仅仅两年前，在美国，他听到伟大的阿尔伯特·迈克尔逊推测物理学几乎已经终结。运动定律和光学定律已被确立，麦克斯韦方程组也把法拉第及其同代人在电和磁之间编织的线索紧紧地连接起来。海因里希·赫兹进一步验证了麦克斯韦的理论，证明无线电波可以被反射、折射、聚焦和偏振——它们本质上就是一种光。然而，现在出现了一种全新的、完全出乎意料的现象：X射线。

Just two years earlier, in the United States, he had heard the great Albert Michelson speculate that physics was all but over. The laws of motion and optics were set firmly in place, and Maxwell’s equations had drawn tight the threads Faraday and his generation had spun between electricity and magnetism. Heinrich Hertz had gone on to verify Maxwell’s theory, showing that radio waves can be reflected, refracted, focused, and polarized—that they are just a kind of light. But here was a new, entirely unexpected phenomenon. X-rays.

米利肯欣慰地意识到，当时普遍的观点是错误的。“即使在基本物理原理方面，我们也远没有我们想象的那么接近宇宙的奥秘。”

The prevailing wisdom, Millikan was happy to realize, had been wrong. “We had not come quite as near sounding the depths of the universe, even in the matter of fundamental physical principles, as we thought we had.”

伦琴射线可以观察手的内部

Roentgen rays look inside a hand

伦琴在研究真空玻璃“放电管”末端出现的发光点时，做出了惊人的发现。当在管内两块金属板（带负电的阴极和带正电的阳极，这两个名称都源自法拉第）之间施加足够大的电压时，就会出现这种发光点。这些阴极射线在稀薄的空气中传播，本身就令人费解。如果在管内设置障碍物——化学家兼唯灵论者威廉·克鲁克斯就用了一个马耳他十字——障碍物的阴影就会出现在发光的玻璃上，这表明射线像子弹一样沿直线运动。如果他把磁铁靠近管子，光束就会偏向一侧。在管内镶嵌一颗宝石，宝石也会发出荧光。这些射线似乎还具有实体，能够带动一个微型桨轮的叶片转动。“这是物质的第四种状态，”克鲁克斯宣称——除了固态、液态、气态和辐射态之外。

Roentgen had made his astonishing discovery while investigating the glowing spot that appears at the end of an evacuated glass “discharge tube” when a large enough voltage is applied across two metal plates inside—a negatively charged cathode and a positively charged anode (names that had come from Faraday). Traveling through the rarefied air, these cathode rays were puzzling enough. If a tube was designed with an obstruction inside—William Crookes, a chemist and spiritualist, used a Maltese cross—its shadow would appear on the fluorescing glass, a clue that the rays moved bulletlike in straight lines. If he held a magnet near the tube, the beam would sway to one side. Mount a gemstone inside and it would fluoresce. The rays also seemed to have substance, turning the vanes of a tiny paddle wheel. “A fourth state of matter,” Crookes claimed—solid, liquid, gaseous, and radiant.

克鲁克斯管：阴极射线可以照亮钻石，投射出马耳他十字的阴影，并带动桨轮沿轨道运动。

Crookes tubes: cathode rays light up a diamond, project a shadow of a Maltese cross, and move a paddle wheel along a track.

伦琴的发现更加奇特：如果射线以足够大的力撞击管端，就会释放出另一种辐射——其威力足以穿透血肉之躯。不到一年后，巴黎的亨利·贝克勒尔发现了另一种穿透性射线，这种射线从铀块中发出，能够穿过不透明的屏蔽层，并在照相底片上留下痕迹。人们很快发现，这两种辐射都能使气体电离，使其带电。我们现在知道，它们是通过击落原子中的电子来实现这一点的。

What Roentgen found was even weirder: if the beam struck the end of the tube with enough force, it unleashed a different kind of radiation—powerful enough to penetrate flesh. Less than a year later Henri Becquerel in Paris discovered another form of penetrating rays emanating from lumps of uranium, passing through an opaque shield and leaving their mark on a photographic plate. Both kinds of radiation, it soon was learned, could ionize a gas, giving it an electrical charge. We know now that they do this by knocking electrons off atoms.

从欧洲返回芝加哥大学任教时，米利肯正与迈克尔逊一起在那儿叱咤风云。他只能远远地关注着欧洲一些最杰出的科学家们对新物理学的探索。在英国剑桥的卡文迪什实验室，J·J·汤姆逊证明，这些光束不仅能被磁铁排斥，还能被强电场排斥。

Returning from Europe to take a job at the University of Chicago, where Michelson now reigned, Millikan watched from afar as some of Europe’s greatest scientists explored the new physics. At the Cavendish Laboratory in Cambridge, England, J. J. Thomson showed that the beams could be repelled not just by magnets but by strong electrical fields.

赫兹本人也曾尝试过这个实验，但失败了。在这个实验中，一束光束在真空管内的平行板之间传播。当用电池给平行板充电后，光束纹丝不动。赫兹认为这意味着射线是以太的一种非物质扰动。（迈克尔逊-莫雷实验的教训仍在他心中酝酿。）

Hertz himself had tried and failed at the experiment, in which a beam travels between parallel plates inside an evacuated tube. When the plates were charged with a battery, the beam didn’t budge. Hertz took this to mean that the rays were an immaterial disturbance of the aether. (The lesson of Michelson-Morley was still sinking in.)

汤姆逊怀疑赫兹没有从电子管中抽出足够的空气——残留的分子就像被雨淋过一样，导致极板短路。通过提高真空度，他能够将电子束向正极移动——这有力地表明阴极射线是由带负电的物质构成的。电粒子。电子。

Thomson suspected that Hertz hadn’t pumped enough air from the tube—that the lingering molecules were shorting out the plates as surely as if they had been rained on. With a better vacuum, he was able to nudge the beam toward the positive pole—a strong indication that cathode rays were made of negatively charged matter. Particles of electricity. Electrons.

汤姆逊实验。阴极射线在C点发射，穿过带正电的阳极（A），然后穿过狭缝B，并在极板D和E之间穿过，最后在管端留下光斑。极板充电会导致光束移动。

J. J. Thomson experiment. Cathode rays are emitted at C, pulled through the positively charged anode (A) then pass through slit B and between plates D and E before leaving a spot on the end of the tube. Charging the plates causes the beam to move.

我原本没打算买汤姆逊管，但它的美实在令人难以抗拒：简洁的木框托着球状的尖头真空管，两侧是巨大的铜制亥姆霍兹线圈（以德国物理学家赫尔曼·冯·亥姆霍兹的名字命名）。线圈间距等于其半径——十五厘米——使真空管处于均匀的磁场中。这台装置产自德国，用于物理课堂教学，从接线盒上灰蒙蒙的龟裂漆面判断，它很可能是上世纪六十年代的产品。

I HADN’T meant to buy my own Thomson apparatus but its beauty was impossible to resist: the simple wooden frame cradling the bulbous, pointed vacuum tube, the large copper Helmholtz coils (named for the German physicist Hermann von Helmholtz) standing at either side. With the spacing between them equal to their radius—fifteen centimeters—they bathe the tube in a uniform magnetic field. The device was made in Germany for use in physics classes, and the grayish crackled finish on the electrical junction box dated it probably to the 1960s.

说明书没附带，只有一张厚厚的绘图纸，上面有人用彩色铅笔画了个电路图：灯丝需要6.3伏电压来加热金属阴极并产生电子，这些电子会被阳极上更高的正电压加速。第三个电源则用来给亥姆霍兹线圈供电。我把电线接到电源上，然后关了灯。

The manual was not included, just a heavy piece of drawing paper on which someone had sketched with colored pencils a wiring diagram: the filament required 6.3 volts to heat the metal cathode and boil off electrons, which would be accelerated by a much larger positive voltage on the anode. A third source of current would energize the Helmholtz coils. I hooked up the wires to my power supply and turned out the lights.

那景象真是诡异。我慢慢提高阳极电压，一团绿色的苹果状雾气在阴极周围聚集，越来越大，越来越浓，直到电压略高于160伏时，一道蓝光突然从阴极的杆子上直射而出，击中了玻璃杯的顶部。就像瓶子里的精灵。这对于克鲁克斯和其他阴极射线管的先驱者来说，该是多么恐怖啊。有些人甚至认为他们看到的是灵质，是鬼魂之类的东西。我用条形磁铁贴在玻璃杯上，让那精灵扭动起来。黑色的磁极把光束引向我，红色的磁极则把它推开。

It was an eerie sight. As I slowly increased the anode voltage, a greenish apple-shaped haze gathered around the cathode, growing larger and fatter until suddenly, a hair above 160 volts, a blue ray of light shot straight up from the stem and struck the top of the glass. The genie in the bottle. How spooky this must have been for Crookes and the other cathode-ray pioneers. Some thought they were seeing ectoplasm. Ghost stuff. Holding a bar magnet to the glass, I made the genie writhe. The black pole beckoned the beam toward me, the red pole pushed it away.

现代版的汤姆逊仪器。艾莉森·肯特绘图

A modern version of the Thomson apparatus. Drawing by Alison Kent

下一步是给线圈通电。我拧动旋钮，光束缓缓弯曲，直到电压达到3.5伏，电流达到0.76安培时，它突然顺时针俯冲，在管内形成一个发光的圆圈。阳极试图将电子向上拉，而这股磁场则将它们吹向侧面——这是一场垂直的拉锯战，汤姆逊意识到，其结果取决于粒子的质量和电荷。他的实验无法单独给出这两个值（质量小、电荷少的粒子与质量大、电荷多的粒子表现相同），但它可以给出它们的比值。

The next step was to energize the coils. As I turned up the knob, the beam slowly bent until—at 3.5 volts, 0.76 amperes—it abruptly dived clockwise and formed a glowing circle inside the tube. While the anode was trying to pull the electrons straight upward, this magnetic wind was blowing them to the side—a perpendicular struggle whose outcome, Thomson had realized, depends on both the mass of the particles and their charge. His experiment can’t tell you either value alone (lightweight particles with a tiny charge would act the same as heavier particles with a larger charge), but it does give you their ratio.

我把数据——阳极电压、线圈电流、发光圆的半径——代入他的公式，然后计算：每克物质的电荷量为 2.5 × 10⁸^库仑。（库仑以法国科学家查尔斯·奥古斯丁·德·库仑的名字命名，大约相当于每秒流过 100 瓦灯泡的电量。）我的结果比公认值大了 50%，但至少我得到了正确的零的个数。

I plugged my numbers—the voltage on the anode, the current in the coils, the radius of the glowing circle—into his equation and did the arithmetic: 2.5 × 10⁸ coulombs of charge per gram. (A coulomb, named in honor of the French scientist Charles-Augustin de Coulomb, is approximately the quantity of electricity flowing each second through a 100-watt bulb.) My result was 50 percent larger than the accepted value, but at least I got the right number of zeros.

更重要的是汤姆逊后来证明的：无论管内气体种类或阴极金属材质如何，都无关紧要。射线比例始终保持不变。所有射线都由同一种物质构成。

More important is what Thomson went on to show: that it didn’t matter what kind of gas was in the tube or what metal he used for the cathode. The ratio remained unchanged. The rays were all made from the same stuff.

那东西真是奇特。氢原子——最轻的元素——在电解池两极间迁移时，其电荷质量比已被测量过。而电子的电荷质量比大约是氢原子的1000倍。要么它带了巨大的电荷，要么正如汤姆逊所怀疑的那样，它比原子小得多。他的直觉告诉他，他发现了一种几乎不可思议的东西：亚原子粒子。

And what strange stuff it was. The ratio of charge to mass had already been measured for the hydrogen atom—the lightest of the elements—as it migrated between the poles of an electrolytic cell. The value for the electron was about a thousand times greater. Either it had an enormous charge, or as Thomson suspected, it was vastly smaller than an atom. His instincts told him he had discovered something almost unthinkable: a subatomic particle.

那是1906年，密立根觉得自己已经过气了——在芝加哥大学任教十年，却依然只是个助理教授。他自认为教得不错，教材也卖得挺好。但他很失望，38岁——对于一位物理学家来说算是年纪大了——却还没有取得任何重大发现。

IT WAS 1906 and Millikan was feeling like a has-been—a decade at Chicago and still an assistant professor. He considered himself an effective teacher, and his textbooks were selling. But he was disappointed that at age thirty-eight, rather old for a physicist, he had made no important discoveries.

他知道，汤姆逊的实验虽然令人印象深刻，但并未最终定论。在人们的认知中，电子可能具有多种不同的电荷和大小，但所有电荷和大小的比例都相同。汤姆逊只是假设它们是相同的。面对这种不确定性，德国人仍然抱持着怀疑的态度，坚持认为电是一种虚无缥缈的波。打破僵局的唯一方法就是测量汤姆逊比例中的一个数值——电子的质量或电荷。

He knew that Thomson’s experiment, impressive as it was, hadn’t clinched the case. For all anyone knew, electrons came in a slew of charges and sizes all yielding the same ratio. Thomson had just assumed they were identical. In the face of this uncertainty, the Germans remained particularly skeptical, clinging to the belief that electricity was an aethereal wave. The only way to break the logjam would be to measure one of the numbers in Thomson’s ratio—either the mass or the charge of the electron.

密立根首先重复了汤姆逊在卡文迪什研究所实验室的一项实验。该实验中，一位科学家测量了带电水蒸气雾（用X射线或镭电离）沉降到密闭容器底部的速度。水雾的上下方分别连接着电池的两极。通过观察电场对水雾下沉速度的影响，就可以计算出水雾的总电荷。用总电荷除以对水雾中带电粒子数量的估计值，就可以粗略估算出电子的平均电荷量。

Millikan began by repeating an experiment in which a scientist in Thomson’s lab at the Cavendish had timed how quickly a charged mist of water vapor—one that had been ionized with X-rays or radium—settled to the bottom of a closed container. Above and below the cloud were metal plates connected to the poles of a battery. By observing the effect of the electrical field on the speed of the cloud’s descent, you could calculate its total charge. Divide that by your guesstimate of how many charged particles were in the cloud and you could rough out an average value for the electron.

这项技术需要用到一种名为威尔逊云室的装置，但它充满了不确定性和假设。蒸汽不断蒸发，导致云团顶部边缘极不规则且模糊不清，追踪其运动轨迹令人沮丧。密立根不断提高电压，希望能够使目标保持稳定——就像穆罕默德的棺材一样悬浮在正负极之间。这样他就可以测量蒸发速率，并将其纳入计算。

The technique, which involved a device called a Wilson cloud chamber, was rife with uncertainty and assumptions. The vapor was continually evaporating, leaving the top edge of the cloud so irregular and indistinct that tracking its motion was an exercise in frustration. Millikan cranked up the voltage, hoping he could hold the target steady—suspended “like Mohammed’s coffin” between positive and negative. Then he could measure the rate of evaporation and account for it in his calculations.

他没有照做，而是打开开关，吹散了云雾。实验失败了……至少表面上看来是这样，直到他注意到几滴水珠仍然悬浮在空中，它们的重量和电荷量恰到好处，足以抵消重力的向下作用力，并被电场产生的悬浮力所抵消。

Instead he flicked on the switch and blew the cloud away. The experiment was a failure…or so it seemed until he noticed that a few individual water drops remained hanging in the air, just the right weight and charge so that the downward pull of gravity was offset by the levitating oomph of the electrical field.

威尔逊云室。打开阀门 B 会产生真空 (C)，将充满潮湿空气的 A 室下方的地板向下吸。体积膨胀导致云的形成。

Wilson cloud chamber. Opening valve B causes a vacuum (C) to suck down the floor beneath chamber A, which is filled with moist air. The expansion of the volume causes a cloud to form.

他意识到，这样就能进行一个更具决定性的实验。他不必研究整团液滴的整体行为，而是可以逐个观察它们。他架设在两英尺外，透过小型望远镜观察，选中一滴悬浮的液滴，然后突然切断电压。他手持秒表，记录液滴在目镜镜筒内下落的时间。他一小时又一小时地记录数据，将估计的液滴重量与维持其悬浮所需的电荷量进行比较。密立根报告说，答案总是“1、2、3、4，或者我所观察到的液滴上最小电荷量的某个其他精确倍数”。电荷似乎确实是以均匀的量存在——他估计是1.55 × 10⁻¹⁹^库仑。

This, he realized, would make for a more decisive experiment. Instead of studying the mass behavior of a whole cloud of drops, he could observe them one by one. Peering through a small telescope set up two feet away, he would pick a drop hovering in suspension and then suddenly turn off the voltage. Stopwatch in hand he timed the fall between the hairlines of his eyepiece. Hour after hour he recorded the data, comparing the estimated weight of a drop with how much charge was required to keep it afloat. The answer, Millikan reported, was always “1, 2, 3, 4, or some other exact multiple of the smallest charge on a droplet that I ever obtained.” Charge indeed seemed to come in uniform portions—what he reckoned to be 1.55 × 10^-19 coulombs.

1909年9月，他前往温尼伯，向英国科学促进协会的会议报告他的研究成果——他当时仍然认为这些成果只是初步的。汤姆逊本人发表了主席致辞，刚刚获得诺贝尔奖的欧内斯特·卢瑟福则就原子物理学的现状作了报告，指出尽管近期取得了诸多成就，“但至今仍未能探测到单个电子”。随后，原本不在会议议程上的密立根却出人意料地宣布，他已经接近实现这一目标。

In September 1909 he traveled to Winnipeg to present the results—he still considered them preliminary—to a meeting of the British Association for the Advancement of Science. Thomson himself gave the presidential address, and Ernest Rutherford, who had just won a Nobel Prize, lectured on the state of atomic physics, noting that for all the recent successes “it has not yet been possible to detect a single electron.” Then Millikan, who wasn’t even on the agenda, surprised everyone by reporting that he had come close to doing just that.

在回家的火车上，他思考着如何才能提出更有说服力的论点。由于蒸发，每一滴水的寿命都以秒计。如果他能追踪一滴水几分钟甚至几小时，调整电压，让它上下波动，那该有多好啊。后来他说，当他凝视着曼尼托巴的平原时，答案瞬间涌现。

On the train back home he thought about how he might make a more persuasive case. Because of evaporation each water drop’s lifetime was measured in seconds. How much better it would be if he could follow a single drop for minutes or even hours, adjusting the voltage and buffeting it up and down. As he was gazing out at the plains of Manitoba, the answer, he later said, came in a flash.

抵达芝加哥后，他请正在寻找论文选题的博士生哈维·弗莱彻帮忙，看看能否用比水滴更持久的物质进行液滴实验。弗莱彻在当地一家药店买了一个香水喷雾器和手表油，开始组装实验器材：两块圆形黄铜板，上面的那块中心钻了一个孔，安装在实验台上，并用强光从侧面照射。他在装置上方喷洒了一层油雾，然后通过望远镜观察。“我看到了非常美丽的景象，”他后来回忆道：

After arriving in Chicago, he asked Harvey Fletcher, a doctoral student who had been looking for a thesis problem, to see if the droplet experiment could be done with something less evanescent than drops of water. Purchasing a perfume atomizer and watch oil at a local drugstore, Fletcher began assembling the equipment: two round brass plates, the top one with a hole drilled at the center, mounted on a lab stand and illuminated from the side by a bright light. He sprayed a mist of oil above the apparatus and watched through a telescope. “I saw a most beautiful sight,” he later recalled:

田野里满是闪烁的小星星，五彩缤纷，宛如彩虹。较大的水滴很快沉入水底，而较小的水滴却仿佛在空中停留了近一分钟，翩翩起舞，美得令人窒息。

The field was full of little starlets, having all the colors of the rainbow. The larger drops soon fell to the bottom, but the smaller ones seemed to hang in the air for nearly a minute. They executed the most fascinating dance.

第二天早上，弗莱彻推来一大组能产生一千伏电压的电池，并将它们连接到黄铜板上。接通电流后，他兴奋地看着一些液滴被缓缓向上推，而另一些则被向下拉，雾化器细小喷嘴的摩擦使它们分别带上了正电荷和负电荷。当米利肯看到这个方案如此奏效时，他欣喜若狂。他和弗莱彻改进了装置，并在接下来的六个月里几乎每天下午都花时间收集数据。

By the next morning Fletcher had wheeled in a large bank of batteries capable of producing one thousand volts and connected them to the brass plates. Turning on the current, he watched with excitement as some of the droplets were pushed slowly upward while others were pulled down, the friction from the tiny nozzle of the atomizer having given them negative or positive charges. When Millikan saw how well the plan was working, he was elated. He and Fletcher refined the setup and spent nearly every afternoon for the next six months taking data.

我的这套装置由英国伯明翰的菲利普·哈里斯公司设计制造，是米利肯装置的简化版，但理念相同。黄铜板安装在一个三脚有机玻璃平台上，平台立于一块约15英寸乘20英寸的深色硬木底座上。光源位于一侧：一个涂有常见实验室灰色的圆柱形金属外壳，带有一个透镜以集中光线。原装的英式灯泡不见了，但我用一个由旧莱昂内尔火车变压器供电的普通卤素灯代替了它。

DESIGNED and crafted by the Philip Harris Company of Birmingham, England, my setup was a streamlined version of Millikan’s. But the idea was the same. The brass plates were mounted inside a three-legged Plexiglas platform that stood on a dark hardwood base measuring about fifteen by twenty inches. Off to one side was the lighting source: a cylindrical metal housing, painted the familiar laboratory gray, with a lens to concentrate the glow. The British-sized bulb was missing, but I was able to substitute an ordinary halogen lamp powered by an old Lionel train transformer.

这是密立根油滴实验的早期版本。油滴穿过针孔落入黄铜板C和D之间的空间，黄铜板C和D通过开关连接到电池。左侧是X射线源，用于将电子从油滴中击出，从而改变油滴的电荷。

Early version of the Millikan oil-drop experiment. Droplets fall through the pinhole and into the space between brass plates C and D, which are connected through a switch to a battery. To the left is an X-ray source used to knock electrons off the drops and change their charge.

后来的版本。商用雾化器 (A) 使用过滤后的空气将油喷入腔室 C，偶尔会有一滴油从腔室 C 中通过顶板 (M) 上的针孔流出。

A later version. A commercial atomizer (A) uses filtered air to spray oil into chamber C from which an occasional drop makes its way through the pinhole in the top plate (M).

为了透过金属板观察跳动的液滴，我安装了一台望远镜（一种结合了望远镜和显微镜功能的装置），它配有一个十字形测量刻度尺，还有一个用于通电的刀闸开关。向上拨动开关，电流就会输送到金属板（“电压不得超过2000伏，”黑色胶木材质的说明书上警告道）。向下拨动开关，则会使金属板短路，从而释放电荷。拆卸所有部件，清理掉灰尘和上千次学生实验中积累的油渍后，我准备开始我的第一次实验。

For peering between the plates at the dancing drops there was a telemicroscope (a cross between a telescope and a microscope) fitted with a crosshatched measuring reticule, and a knife switch for applying the electricity. Up sent power to the plates (“Do not exceed 2,000 volts,” warned the black Bakelite instruction panel.) Down shorted them together and dispelled the charge. After disassembling the parts to clean out dust and the accumulated oil of a thousand student experiments, I was ready for my first run.

菲利普·哈里斯公司密立根仪器。艾莉森·肯特绘图

Philip Harris Co. Millikan apparatus. Drawing by Alison Kent

我用普通的矿物油装满一个香水喷雾器，然后喷入顶部黄铜板上方的腔室。接着，我等待几滴油滴从小孔中落下。它们看起来更像是阳光照射下的尘埃，而不是小星星。但这种效果却令人着迷。我会挑选一滴缓慢笔直下落的油滴，然后接通电极板的电压。如果它突然开始向上移动，我就知道它带电了。我拨动刀闸开关，调节电压，记录油滴在目镜的细线间上升和下降的时间——下降4.2秒，上升2.6秒……下降6.8秒，上升4.0秒……7.1秒，上升2.2秒……8.1秒，上升3.3秒。

I loaded a perfume atomizer with ordinary mineral oil and sprayed it into the chamber above the top brass plate. Then I waited for a few droplets to fall through the tiny hole. They looked more like dust motes in a shaft of sunlight than like little stars. But the effect was hypnotizing. I’d pick out one that was falling straight and slow and switch on the plate voltage. If it suddenly began moving upward I knew that it carried a charge. Flipping the knife switch up and down and adjusting the voltage, I’d time the drops as they rose and fell between the hairlines in the eyepiece—4.2 seconds down, 2.6 secondsup…6.8 down, 4.0 up…7.1 and 2.2…8.1 and 3.3.

我开始慢慢掌握诀窍了。但要准确操作，我需要抓住一滴液体足够长的时间，观察上升时间的突然变化，这表明它获得了或失去了一个电子。当我收集了十几滴液体的数据，并用斯托克斯定律估算出它们的质量后，就可以计算出电荷的基本单位了。

I was starting to get the hang of it. But to do this right I needed to grab on to a single drop long enough to watch for the sudden variations in rise time, which would signal that it had gained or lost an electron. When I’d collected the data for a dozen drops and estimated their masses (with an equation called Stokes’s law), I could calculate the fundamental unit of charge.

这些事情在物理书上听起来都那么简单。你不会听说黄铜板因为金属夹子滑错位置而短路冒火花，也不会听说喷油过多堵塞针孔。我会把一滴液体和另一滴混淆，或者把它和眼里的飞蚊症搞混。我会锁定看似完美的样本，然后眼睁睁地看着它漂离焦平面。有时，一滴液体太重，像石头一样沉入水底；有时，它携带的电荷太多，以至于我接通电压后，它就瞬间消失不见。我尝试了太多次，失败了太多次，才意识到：对我来说，掌握如此精细的实验就像学习拉小提琴，或者至少学会做木工一样难。

These things sound so easy in the physics books. You don’t hear about the brass plates shorting out and sparking because a metal clip slipped into the wrong position. Or about spraying too much oil and clogging the pinhole. I’d confuse one drop with another or with a floater in my eye. I’d lock on to what seemed the perfect specimen and then watch helplessly as it drifted out of the focal plane. Sometimes a drop would be so heavy that it sank like a stone, or carry so much charge that when I turned on the voltage it rocketed out of sight. I tried and failed too many times before I realized: for me to master so delicate an experiment would be like learning to play the violin or at least make good cabinetry.

米利肯大师的技艺如此精湛，他只需用枪瞄准器捕捉一滴油，然后回家吃晚饭，晚上回来时，油滴几乎纹丝不动。他的助手弗莱彻在他身边，他会一边观察电子在油滴上跳跃的速度变化，一边像旧金山缆车上的乘客一样发出信号。如果电子需要加速，他会打开一扇小小的铅门，用镭照射它们。

MAESTRO Millikan’s touch was so deft that he could snag an oil drop in his gun sights, go home for dinner, and return later that evening to find it had barely moved. With his assistant Fletcher at his side, he’d call out the changes in speed as electrons hopped on and off a droplet like passengers riding a San Francisco cable car. If they needed a little boost, he opened a small lead door and zapped them with radium.

他关于水滴的数据已经遭到一位奥地利实验家的质疑，这位实验家很快声称发现了“亚电子”，并怀疑不存在最小的电荷单位。但油滴实验却充分证实了密立根早期较为粗糙的实验结果：电子确实存在。一天下午，先驱电气工程师查尔斯·普罗透斯·斯坦梅茨前来观看实验。“我简直不敢相信，”他握着弗莱彻的手说，“我简直不敢相信。”

His data on the water drops had already come under attack from an Austrian experimenter who soon was claiming to have found “subelectrons” and suspected that there was no smallest unit of charge. But what Millikan had found with his earlier, cruder experiment was confirmed in spades by the oil drops. There really were electrons. One afternoon, Charles Proteus Steinmetz, the pioneering electrical engineer, came to watch the experiments. “I never would have believed it,” he said, shaking Fletcher’s hand. “I never would have believed it.”

1910年初，他们开始整理实验结果。在接下来的三年里，密立根不断改进实验。最初简单的桌面装置逐渐演变成一台高科技设备，配备了过滤空气、精确控制的温度、压力和电压，以及能够以毫秒为单位计时的时钟。同样重要的是，他在解读液滴变化方面取得了进展。他将液滴的波动记录在笔记本中：

Early in 1910 they began writing up the results, and over the next three years Millikan continued to improve the experiment. The simple tabletop contraption morphed into a high-tech device with filtered air, tightly regulated temperature, pressure, and voltage, and a clock capable of marking time in milliseconds. Just as important was his progress in learning to read the drops. He recorded the ups and downs in his notebook:

非常低，肯定有问题……不确定距离……可能是双重坠落……发布精美图片……非常适合非常小的……完全正确……出了点问题……行不通……发布这个精美图片。

Very low something wrong…not sure of distance…Possibly a double drop…Beauty Publish…Good one for very small one…Exactly Right…Something the matter…Will not work out…Publish this Beautiful one.

随着他反应速度的提升，美女出现的频率也随之增加：

As he tuned his reflexes the frequency of beauties increased:

完美发布……迄今为止最好的一次。

Perfect Publish…Best one yet.

仿佛电子本身在光线下闪烁。

It was as though the electrons themselves were shimmering in the light.

“凡是看过那个实验的人……实际上就看到了电子， ”密立根后来写道，他特意用斜体字强调了这一点。“他能像数清自己的手指和脚趾一样，准确地数出给定小电荷中的电子数量。”

“He who has seen that experiment…has in effect SEEN the electron,” Millikan later wrote, italicizing his italics. “He can count the number of electrons in a given small electrical charge with exactly as much certainty as he can attain in counting his fingers and his toes.”

1913年，他发表了电荷基本单位的最终值：1.5924 × 10⁻¹⁹^库仑。（如今公认的值略高一些，为 1.60217653 × 10⁻¹⁹ ^。）十年后，他获得了诺贝尔奖。

In 1913 he published his definitive value for the basic unit of electrical charge: 1.5924 × 10^-19 coulomb. (The accepted value today is just slightly higher, 1.60217653 × 10^-19.) Ten years later he was awarded a Nobel Prize.

这个故事的结局颇为奇特。1981年，密立根的前助手哈维·弗莱彻去世后，一本回忆录浮出水面，书中既描述了他对密立根提携其事业的感激之情，也描述了他对油滴实验未能获得更多认可的失望。据弗莱彻回忆，有一天，他的教授突然出现在他的公寓，提出一项交易：密立根将独自署名关于电子电荷的论文，而弗莱彻则将因一项不太重要的合作而获得全部荣誉。

THE STORY has a strange denouement. After Millikan’s former assistant, Harvey Fletcher, died in 1981, a memoir surfaced describing both his appreciation to Millikan for advancing his career and his disappointment at not getting more recognition for the oil-drop experiment. As Fletcher told the story, his professor showed up unexpectedly one day at his apartment offering to cut a deal. Millikan would be the sole author of the paper on the charge of the electron, but Fletcher would get full credit for a less important collaboration.

弗莱彻坚持要求在他去世后发表他的记录，这增加了记录的可信度，但也剥夺了密立根（已于1953年去世）回应的机会。从密立根的自传来看，你肯定不想和他一起被困在荒岛上，甚至不想和他一起乘坐横跨美国的航班。他有时会显得居高临下，甚至有些偏执。尽管他是分离和测量电子的幕后功臣，但他或许可以对他的学生更宽容一些。这项实验的精髓在于实验本身，而非实验者。

Fletcher’s insistence that his account be published posthumously added to its credibility but also denied Millikan (who had died in 1953) an opportunity to respond. Judging from his autobiography, Millikan was not someone you’d want to be stuck with on a desert island, or even a cross-country flight. He could be patronizing and even a little bigoted. Though he was the indisputable force behind the isolation and measurement of the electron, he probably could have been more generous to his student. The beauty here lies with the experiment not the experimenter.

更令人不安的是，后来又出现了关于密立根篡改数据的指控。从档案馆中找到的密立根实验室日志中的批注被解读为他精心筛选数据以迎合其预设结论的证据。

More troubling were accusations, coming still later, that Millikan had cooked the books. The annotations in his laboratory journals, retrieved from the archives, were construed as evidence that he had combed his data for results that supported his preconceptions.

对于经历过油滴实验的人来说，这种指责并不成立。我怀疑，密立根只是对实验机制有了感觉，一种第六感，能预感到哪里出了问题：秒表上的拇指滑了一下，温度或极板电压突然波动，或者一粒灰尘冒成了油滴。他知道自己什么时候实验出了差错。

This is not an accusation that rings true to someone who has struggled with the oil-drop experiment. Millikan, I suspect, had simply developed a feeling for the mechanism, a sixth sense for when something had gone wrong: a slip of the thumb on the stopwatch, a sudden fluctuation in temperature or plate voltage, a dust particle masquerading as an oil drop. He knew when he had a bad run.

比那些毫无根据的指控更有意思的是如何避免将直觉与臆测混淆，从而避免像使用通灵板一样，无意识地影响实验装置，使其得出预期的答案。这是每位实验者都必须面对的挑战。而最难以捉摸的实验室设备，永远是人脑。

More interesting than the unfounded allegations is the question of how you keep from confusing your instincts with your suppositions, unconsciously nudging the apparatus, like a Ouija board, to come up with the hoped-for reply. It’s something every experimenter must struggle with. The most temperamental piece of laboratory equipment will always be the human brain.

后记

Afterword

第十一届最美实验

The Eleventh Most Beautiful Experiment

2006年秋天，我担任加州圣巴巴拉卡弗里理论物理研究所的驻所科学作家期间，做了一场关于“十大最美实验”的演讲。演讲结束后，一位女士走过来问我，为什么书中只有男性实验者。

IN THE AUTUMN of 2006, while I was science writer in residence at the Kavli Institute for Theoretical Physics in Santa Barbara, California, I gave a talk on The Ten Most Beautiful Experiments. Afterward a woman came forward to ask why there would be only men in the book.

我原本想把玛丽·居里列入名单，因为她发现了镭，她费尽心力从数吨放射性矿石中提炼出一小滴这种发光物质。但我觉得这更像是一次英勇的探险，而不是对自然界的可控探索。莉泽·迈特纳似乎更合适，但她在20世纪30年代进行的核裂变开创性实验是与奥托·哈恩和弗里茨·斯特拉斯曼合作完成的。科学已经开始发展成如今这种协作式的事业。宣布发现顶夸克的论文上就有439个名字。

I’d thought of including Marie Curie for her discovery of radium, laboriously distilling a smidgen of the glowing stuff from tons of radioactive ore. But that struck me as more of a heroic exploration than a controlled interrogation of nature. Lise Meitner seemed a likelier candidate, but her pioneering experiments in nuclear fission in the 1930s were done with Otto Hahn and Fritz Strassmann. Science was already becoming the collaborative effort that it is today. There were 439 names on the paper announcing the discovery of the top quark.

如果我要突破我任意设定的界限，那么第十一个最美丽的实验可能是丽塔·列维-蒙塔尔奇尼发现神经生长因子，芭芭拉·麦克林托克对基因调控和跳跃基因的研究，或者吴建雄光荣地证明衰变的电子违反了宇称守恒定律。

If I were to go beyond my arbitrary cutoff, maybe the eleventh most beautiful experiment would be Rita Levi-Montalcini’s discovery of nerve-growth factor, Barbara McClintock’s work on genetic regulation and jumping genes, or Chien-Shiung Wu’s glorious demonstration that decaying electrons violate a law called conservation of parity.

我才刚看完这本书，就已经开始怀疑自己了。为什么不讲讲卢瑟福和原子核、詹姆斯·查德威克和中子，或者海克·卡末林·昂内斯和超导性呢？生物学领域有格雷戈尔·孟德尔在花园里进行的遗传学实验，还有奥斯瓦尔德·艾弗里证明基因是由DNA构成的，阿尔弗雷德·赫尔希和玛莎·蔡斯著名的沃林搅拌机实验更是完美地印证了这一点。马修·梅塞尔森和富兰克林·斯塔尔进行的实验被一些人称为生物学中最美妙的实验，他们证实了DNA的复制方式与沃森和克里克双螺旋结构的预测一致。

I’ve barely finished the book and already I’m second-guessing myself. Why not Rutherford and the atomic nucleus, James Chadwick and the neutron, or Heike Kamerlingh Onnes and superconductivity? In biology there were Gregor Mendel with his garden experiments in genetics, and Oswald Avery, who showed that genes are made from DNA, a point beautifully driven home by Alfred Hershey and Martha Chase’s famous Waring blender experiment. In what some have called the most beautiful experiment in biology Matthew Meselson and Franklin Stahl confirmed that DNA replicates as predicted by Watson and Crick’s double helix.

随着二十世纪的流逝，可供探索的自然奥秘越来越少，大自然紧紧地守护着仅存的秘密。或许，我们再也无法像过去那样，将一块不为人知的脚手架碎片摆放在桌面上。但谁也说不准。或许，第十一个最美妙的实验尚未到来。

As the twentieth century wears on, the pickings grow slimmer, with nature holding tightly to what secrets remain. The days when an unknown piece of the scaffolding could be exposed on a tabletop might be behind us. But you never know. The eleventh most beautiful experiment may be yet to come.

注释和参考书目

NOTES AND BIBLIOGRAPHY

这些笔记旨在兼作推荐阅读清单，书籍按章节分组。由于网络瞬息万变，且网址在纸面上显示不清晰（并非为方便阅读而设计），我已将网络资源的链接放在我的个人网站 talaya.net 上，读者也可以在那里找到其他补充材料。

THESE NOTES are intended to serve double duty as a suggested reading list, with the books grouped chapter by chapter. Because of the mercurial nature of the Web and the jagged appearance of URLs (never meant for human consumption) on the printed page, I’ve put links to Internet resources on my own site, talaya.net, where readers can find other supplementary material as well.

“就像我自己的讣告一样”：保罗·阿瑟·希尔普，《阿尔伯特·爱因斯坦：哲学家-科学家》（伊利诺伊州拉萨尔：开放法庭出版社，1979 年，原版出版于 1949 年），第 3、9 页。

“something like my own obituary”: Paul Arthur Schilpp, Albert Einstein: Philosopher-Scientist (La Salle, Ill.: Open Court, 1979, originally published 1949), pp. 3, 9.

序幕

Prologue

“这一液滴的出现”：罗伯特·密立根，《物理评论》 32（1911）：349，摘自莫里斯·H·沙莫斯，《物理学中的伟大实验》（纽约：多佛出版社，1987 年），第 243 页。

“The appearance of this drop”: Robert Millikan, Physical Review 32 (1911): 349, excerpted in Morris H. Shamos, Great Experiments in Physics (New York: Dover, 1987), p. 243.

《物理世界》杂志于 2002 年 9 月发表了一项调查（罗伯特·P·克里斯，《最美丽的实验》，第 19-20 页），该调查构成了克里斯的著作《棱镜与钟摆：科学中最美丽的十大实验》（纽约：兰登书屋，2003 年）的基础。

The Physics World survey appeared in September 2002 (Robert P. Crease, “The Most Beautiful Experiment,” pp. 19–20) and formed the basis of Crease’s book The Prism and the Pendulum: The Ten Most Beautiful Experiments in Science (New York: Random House, 2003).

“个人优先性问题”：引自西尔瓦努斯·菲利普斯·汤普森所著《开尔文勋爵传》第一卷，第二版（纽约：切尔西出版社，1976 年），第 292 页。

“Questions of personal priority”: Quoted in the first volume of Silvanus Phillips Thompson, The Life of Lord Kelvin, 2nd ed. (New York: Chelsea, 1976), p. 292.

1.伽利略：事物运动的真正方式

1. Galileo: The Way Things Really Move

德雷克，斯蒂尔曼。《伽利略研究：个性、传统与革命》。安娜堡：密歇根大学出版社，1970年。

Drake, Stillman. Galileo Studies: Personality, Tradition, and Revolution. Ann Arbor: University of Michigan Press, 1970.

——. 《伽利略的工作：他的科学传记》。芝加哥：芝加哥大学出版社，1978年。

———. Galileo at Work: His Scientific Biography. Chicago: University of Chicago Press, 1978.

伽利略，《关于两门新科学的对话》 。亨利·克鲁和阿方索·德·萨尔维奥译。“伟大思想家系列”。纽约州布法罗：普罗米修斯出版社，1991年；原版出版于1914年。

Galilei, Galileo. Dialogues Concerning Two New Sciences. Translated by Henry Crew and Alfonso de Salvio. Great Minds Series. Buffalo, N.Y.: Prometheus, 1991; originally published 1914.

——。《两门新科学，包括重心和冲击力》。斯蒂尔曼·德雷克译。第二版。纽约：现代图书馆，2001年；原版出版于1974年。

———. Two New Sciences, Including Centers of Gravity & Force of Percussion. Translated by Stillman Drake. 2nd ed. New York: Modern Library, 2001; originally published 1974.

科斯特勒，亚瑟。《梦游者：人类对宇宙的认知变迁史》。纽约：麦克米伦出版社，1959年。

Koestler, Arthur. The Sleepwalkers: A History of Man’s Changing Vision of the Universe. New York: Macmillan, 1959.

罗兰，韦德。《伽利略的错误：重新审视伽利略与教会之间的史诗级对抗》。美国第一版。纽约：Arcade出版社，2003年。

Rowland, Wade. Galileo’s Mistake: A New Look at the Epic Confrontation Between Galileo and the Church. 1st U.S. ed. New York: Arcade, 2003.

Shea, William R. 和 Mariano Artigas。《罗马的伽利略：一个麻烦天才的兴衰》。纽约：牛津大学出版社，2003 年。

Shea, William R., and Mariano Artigas. Galileo in Rome: The Rise and Fall of a Troublesome Genius. New York: Oxford University Press, 2003.

索贝尔，达瓦。《伽利略的女儿：科学、信仰与爱的历史回忆录》。纽约：沃克出版社，1999年。

Sobel, Dava. Galileo’s Daughter: A Historical Memoir of Science, Faith, and Love. New York: Walker, 1999.

题词：伽利略·伽利莱，《关于两门新科学的论述与数学论证》，载于《伽利略·伽利莱全集》（ Le Opere di Galileo Galilei），国家版（佛罗伦萨：G. Barbèra出版社，1890年），第204页。亨利·克鲁和阿方索·德·萨尔维奥将其译为英文，书名为《关于两门新科学的对话录》（Dialogues Concerning Two New Sciences），斯蒂尔曼·德雷克将其译为《两门新科学》（Two New Sciences）。引文出自克鲁的译本；页码出自《伽利略·伽利莱全集》，德雷克也采用了该书的页码。

epigraph: Galileo Galilei, Discorsi e dimostrazioni matematiche intorno a due nuove scienze, published in Le Opere di Galileo Galilei, edizione nazionale (Firenze: Tip. di G. Barbèra, 1890), p. 204. Translated into English by Henry Crew and Alfonso de Salvio as Dialogues Concerning Two New Sciences and by Stillman Drake as Two New Sciences. Quotations are from the Crew translation; pagination is from Le Opere, which Drake also uses.

揭穿伽利略：阿瑟·库斯勒在《梦游者》第 425-509 页中措辞尤为严厉。

debunking Galileo: Arthur Koestler is particularly harsh in The Sleepwalkers, pp. 425–509.

“现在你不会再躲在后面了”：Opere，第 109 页。

“Now you would not hide behind”: Opere, p. 109.

“一块木制装饰条或木料”：同上，第 213 页。

“A piece of wooden moulding or scantling”: Ibid., p. 213.

好得有点不真实：参见 Paul D. Sherman，“伽利略与斜面之争”，《物理教师》 12 (1974): 343–48。

a little too good to be true: See Paul D. Sherman, “Galileo and the Inclined Plane Controversy,” Physics Teacher 12 (1974): 343–48.

“一个青铜球滚动……！”：亚历山大·科伊雷，《测量实验》，美国哲学学会会刊97，第 2 期（1953 年）：222-37。

“A bronze ball rolling…!”: Alexandre Koyré, “An Experiment in Measurement,” Proceedings of the American Philosophical Society 97, no. 2 (1953): 222–37.

斯蒂尔曼·德雷克论伽利略的斜面实验：“音乐在伽利略实验中的作用”，《科学美国人》 232，第6期（1975年6月）：98-104。

Stillman Drake on Galileo’s inclined-plane experiment: “The Role of Music in Galileo’s Experiments,” Scientific American 232, no. 6 (June 1975): 98–104.

伽利略本可以从奇数级数入手：欲了解德雷克分析的更多层面，请参阅《科学美国人》 228卷5期（1973年5月）第84-92页的《伽利略发现自由落体定律》；他翻译的《两门新科学》的导言；以及他收录于第二版附录的论文《发现自由落体定律》。他的著作《伽利略研究》（第214-239页）和《伽利略的工作》（第76-90页）中还有更多相关内容。

Galileo could have started with the odd-number progression: For more layers of Drake’s analysis, see “Galileo’s Discovery of the Law of Free Fall,” Scientific American 228, no. 5 (May 1973): 84–92; the introduction to his translation of Two New Sciences; and his essay “Discovery of the Law of Fall,” which is appended to the second edition. There is still more on the subject in his books Galileo Studies, pp. 214–39, and Galileo at Work, pp. 76–90.

Thomas Settle 对该实验的重建：“科学史上的一个实验”，《科学》 133 (1961): 19–23。

Thomas Settle’s reconstruction of the experiment: “An Experiment in the History of Science,” Science 133 (1961): 19–23.

“管弦乐队的指挥”：“音乐的作用”，第 98 页。

“The conductor of an orchestra”: “Role of Music,” p. 98.

“即使在他那个时代”：同上，第 100 页。

“Even in his day”: Ibid., p. 100.

2.威廉·哈维：《心之奥秘》

2. William Harvey: Mysteries of the Heart

奥布里，约翰和奥利弗·劳森·迪克。《奥布里的短暂人生》。安娜堡：密歇根大学出版社，1957 年。

Aubrey, John, and Oliver Lawson Dick. Aubrey’s Brief Lives. Ann Arbor: University of Michigan Press, 1957.

哈维，威廉。《论动物心脏和血液的运动》。罗伯特·威利斯译。“伟大思想家系列”。纽约州布法罗：普罗米修斯出版社，1993年；原版出版于1910年。

Harvey, William. On the Motion of the Heart and Blood in Animals. Translated by Robert Willis. Great Minds Series. Buffalo, N.Y.: Prometheus, 1993; originally published 1910.

——。《威廉·哈维著作集》。罗伯特·威利斯译。医学与生物学经典丛书。费城：宾夕法尼亚大学出版社，1989年；原版出版于1965年。

———. The Works of William Harvey. Translated by Robert Willis. Classics in Medicine and Biology Series. Philadelphia: University of Pennsylvania Press, 1989; originally published 1965.

凯恩斯，GL，《威廉·哈维传》。纽约：牛津大学出版社，1966年。

Keynes, G. L. The Life of William Harvey. New York: Oxford University Press, 1966.

Pagel, Walter.威廉·哈维的生物学思想：若干方面和历史背景。瑞士巴塞尔：S. Karger，1967 年。

Pagel, Walter. William Harvey’s Biological Ideas: Selected Aspects and Historical Background. Basel, Switzerland: S. Karger, 1967.

———.威廉·哈维新视角。瑞士巴塞尔：S. Karger，1983年。

———. New Light on William Harvey. Basel, Switzerland: S. Karger, 1983.

帕克，罗斯韦尔。《医学史概要》。费城：FA Davis出版社，1897年。

Park, Roswell. An Epitome of the History of Medicine. Philadelphia: F. A. Davis, 1897.

题词：哈维，《论动物心脏和血液的运动》。（我使用了哈维著作中的章节和段落编号。）

epigraph: Harvey, On the Motion of the Heart and Blood in Animals. (I have used Harvey’s chapter and paragraph numbers.)

“在可见与不可见之间”：心的运动， IV.17。

“Betwixt the visible and invisible”: Motion of the Heart, IV.17.

“仿佛透过窗户看到了它”：同上，IV.16。

“as though it had been seen through a window”: Ibid., IV.16.

关于哈维的生平细节，最好的资料来源是凯恩斯所著的《威廉·哈维传》。

The best source of biographical details for Harvey is Keynes, The Life of William Harvey.

“他常说”：奥布里的《简短人生》，第 130-131 页。

“He was wont to say”: Aubrey’s Brief Lives, pp. 130–31.

“因为我既不能正确地感知”：心的运动， I.1。

“For I could neither rightly perceive”: Motion of the Heart, I.1.

“大量地，猛烈地”：同上，IX.8。

“abundantly, impetuously”: Ibid., IX.8.

“这两个动作”：同上，V.3-6。

“These two motions”: Ibid., V.3–6.

“微观世界的太阳”：同上，第八章第三节。

“the sun of the microcosm”: Ibid., VIII.3.

“正如上帝用空气使人红润一样”：斯蒂芬·芬尼·梅森，《科学史》，新修订版（纽约：科利尔出版社，1962 年），第 219 页。

“Just as by air God makes ruddy”: Stephen Finney Mason, A History of the Sciences, new rev. ed. (New York: Collier, 1962), p. 219.

哈维决定进行计算：心脏的运动， IX.2-5。

Harvey decided to do the math: Motion of the Heart, IX.2–5.

“如果将一条活蛇剖开”：同上，X.6-7。

“If a live snake be laid open”: Ibid., X.6–7.

“批评者、戏子和作家”：“致约翰·里奥兰的第二篇论述”，威廉·哈维作品集，第 109 页。

“detractors, mummers, and writers”: “A Second Disquisition to John Riolan,” The Works of William Harvey, p. 109.

“但他经常说”：奥布里的《简短人生》，第 128 页。

“But he often sayd”: Aubrey’s Brief Lives, p. 128.

3.艾萨克·牛顿：什么是颜色

3. Isaac Newton: What a Color Is

福维尔，约翰编。《让牛顿存在！》重印版。纽约：牛津大学出版社，1990 年。

Fauvel, John, ed. Let Newton Be! Reprint. New York: Oxford University Press, 1990.

费恩戈尔德，莫迪凯。《牛顿时刻：艾萨克·牛顿与现代文化的形成》。纽约：牛津大学出版社，2004年。

Feingold, Mordechai. The Newtonian Moment: Isaac Newton and the Making of Modern Culture. New York: Oxford University Press, 2004.

格莱克，詹姆斯。《艾萨克·牛顿》。纽约：万神殿出版社，2003年。

Gleick, James. Isaac Newton. New York: Pantheon, 2003.

Hall, A. Rupert.《万物皆光：牛顿光学导论》。重印版。纽约：牛津大学出版社，1995 年。

Hall, A. Rupert. All Was Light: An Introduction to Newton’s Opticks. Reprint. New York: Oxford University Press, 1995.

胡克，罗伯特。《显微图谱；或，用放大镜对微小物体进行的一些生理描述，以及相关的观察和探究》。多佛凤凰出版社，纽约州米尼奥拉：多佛出版社，2003年。

Hooke, Robert. Micrographia; or, Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses, with Observations and Inquiries Thereupon. Dover Phoenix Editions, Mineola, N.Y.: Dover, 2003.

Sabra，《光的AI理论：从笛卡尔到牛顿》。纽约：剑桥大学出版社，1981年。

Sabra, A. I. Theories of Light: From Descartes to Newton. New York: Cambridge University Press, 1981.

韦斯特福尔，理查德·S. 《永不停歇：艾萨克·牛顿传》。纽约：剑桥大学出版社，1980年。

Westfall, Richard S. Never at Rest: A Biography of Isaac Newton. New York: Cambridge University Press, 1980.

题词：摘自《显微图谱》序言（无页码）。

epigraph: From the preface of Micrographia (unpaginated).

有关光学早期历史，请参阅 Sabra 的《光的理论》。

For the early history of optics, see Sabra, Theories of Light.

笛卡尔在他的著作《流星》中描述了他关于装满水的球的实验，该著作摘自威廉·弗朗西斯·马吉的《物理学资料汇编》（纽约、伦敦：麦格劳-希尔出版社，1935 年），第 273-278 页。

Descartes describes his experiment with the water-filled sphere in his treatise “Les Méteores,” which is extracted in William Francis Magie, A Source Book in Physics (New York, London: McGraw-Hill, 1935), pp. 273–78.

“蓝色是视网膜上的印象”：霍尔，《万物皆光》，第 18 页。

“Blue is an impression on the Retina”: Hall, All Was Light, p. 18.

牛顿早期的光学实验在他的论文《论颜色》（剑桥大学图书馆附加手稿 3975，第 1-22 页）中有描述，并在《艾萨克·牛顿》 （第 79-89 页）、《永不停歇》（第 93-96 页）和《万物皆光》（第 33-38 页）中进行了总结和解释。牛顿的所有科学手稿——以及他关于炼金术和宗教的著作——都可以通过牛顿项目在线获取。

Newton’s early optical experiments are described in his paper Of Colours (Cambridge University Library Add. Ms. 3975, pp. 1–22) and summarized and interpreted in Isaac Newton, pp. 79–89, Never at Rest, pp. 93–96, and All Was Light, pp. 33–38. All of Newton’s scientific manuscripts—as well as his writings on alchemy and religion—are available online through the Newton Project.

“眨眨你的眼睛，点燃一支蜡烛”：论色彩， 1。（我使用了手稿中的段落编号。）

“twixt your eye & a candle”: Of Colours, 1. (I have used the paragraph numbers from the manuscript.)

远离瘟疫：牛顿光学实验的确切时间顺序有些混乱，人们有理由怀疑其中有多少工作是在伍尔索普完成的，又有多少是在剑桥完成的。参见《永不停歇》，第156-158页。

Shut away from the plague: The precise chronology of Newton’s optical experiments is somewhat confused, and there is reason to wonder how much of the work was performed in Woolsthorpe and how much in Cambridge. See Never at Rest, pp. 156–58.

“众多反射面”：论色彩， 56。

“multitude of reflecting surface”: Of Colours, 56.

“正如眼镜所显示的那样”：同上，第 36 页。

“Accordingly as the glasses”: Ibid., 36.

“在我的眼睛和骨头之间”：同上，58-60。

“betwixt my eye & the bone”: Ibid., 58–60.

“来自中心格林”：同上，62-63。

“from the center greene”: Ibid., 62–63.

“大量的这种细长管道”：同上，第 64 页。

“a vast multitud of these slender pipes”: Ibid., 64.

“深红色”：同上，第 6 页。

“good deepe red”: Ibid., 6.

关于百叶窗和棱镜的实验描述见于《光与色彩理论》的誊清稿（剑桥大学图书馆，Add. Ms. 3970.3ff.），第460-466页。该实验后来以《关于光与色彩的新理论》为题发表于《皇家学会哲学汇刊》第80卷（1671年2月19日至1672年）。这两个版本均可在牛顿项目网站上在线查阅。关于该实验的叙述和分析，请参阅《永不停歇》（Never at Rest）第156-175页和《光理论》（Theories of Light）第234-244页。

The experiment with the window shutter and prism is described in “Fair Copy of ‘A Theory Concerning Light and Colors’” (Cambridge University Library, Add. Ms. 3970.3ff.), pp. 460–66. It was later published as “New Theory About Light and Colors,” Philosophical Transactions of the Royal Society 80 (19 February 1671–1672). Both versions are online at the Newton Project. For narratives and analyses of the experiment, see Never at Rest, pp. 156–75, and Theories of Light, pp. 234–44.

“起初，这是一种非常令人愉快的消遣”：此处所有引文均出自《光与色彩理论》。

“It was at first a very pleasing divertisement”: All quotations here are from “Theory Concerning Light and Colors.”

大量的实验：韦斯特福尔在《永不停歇》第 94-96 页详细阐述了这些实验，并指出早在 1664 年，牛顿在剑桥就对白光的异质性有所预感。

a multitude of experiments: Westfall lays out the details in Never at Rest, pp. 94–96, and notes that Newton had a hunch about the heterogeneity of white light as early as 1664 in Cambridge.

“吹出的光线遭受痛苦”：色彩， 6。

“blew rays suffer”: Of Colours, 6.

“由折射率不同的光线组成”：“光与色理论”。

“consists of rayes differently refrangible”: “Theory Concerning Light and Colors.”

“折射程度相同”：同上。

“To the same degree of refrangibility”: Ibid.

“明亮的云”：“博学的弗朗西斯·利纳斯先生的一封信……探讨牛顿先生的光与色理论”和“对此信的答复”，《皇家学会哲学汇刊》 110（1674年1月25日至1675年）。可在牛顿项目网站上在线查阅。

“bright cloud”: “A Letter of the Learn’d Franc. Linus…animadverting upon Mr Newtons Theory of Light and Colors” and “An Answer to this Letter,” Philosophical Transactions of the Royal Society 110 (25 January 1674–1675). Available online at the Newton Project.

4.安托万-洛朗·拉瓦锡：《农家女》

4. Antoine-Laurent Lavoisier: The Farmer’s Daughter

贝尔，麦迪逊·斯马特。《拉瓦锡元年：革命时代新科学的诞生》。纽约：诺顿出版社，2005年。

Bell, Madison Smartt. Lavoisier in the Year One: The Birth of a New Science in an Age of Revolution. New York: Norton, 2005.

杰拉西，卡尔和罗尔德·霍夫曼。《氧气：两幕剧》。纽约：Wiley-VCH，2001 年。

Djerassi, Carl, and Roald Hoffmann. Oxygen: A Play in Two Acts. New York: Wiley-VCH, 2001.

多诺万，阿瑟。《安托万·拉瓦锡：科学、行政与革命》。新版。纽约：剑桥大学出版社，1996 年。

Donovan, Arthur. Antoine Lavoisier: Science, Administration and Revolution. New ed. New York: Cambridge University Press, 1996.

盖尔拉克，亨利。《安托万-洛朗·拉瓦锡：化学家和革命家》。纽约：斯克里布纳出版社，1975年。

Guerlac, Henry. Antoine-Laurent Lavoisier, Chemist and Revolutionary. New York: Scribner, 1975.

——拉瓦锡——关键的一年：1772 年他首次进行燃烧实验的背景和起源。伊萨卡，纽约：康奈尔大学出版社，1961 年。

———. Lavoisier—The Crucial Year: The Background and Origin of His First Experiments on Combustion in 1772. Ithaca, N.Y.: Cornell University Press, 1961.

Holmes, Frederic Lawrence. Antoine Lavoisier: The Next Crucial Year; or, The Sources of his Quantitative Method in Chemistry. Princeton, NJ: Princeton University Press, 1998.

Holmes, Frederic Lawrence. Antoine Lavoisier: The Next Crucial Year; or, The Sources of His Quantitative Method in Chemistry. Princeton, N.J.: Princeton University Press, 1998.

拉瓦锡，安托万-洛朗。《化学原理》。纽约：多佛出版社，1965年。

Lavoisier, Antoine-Laurent. Elements of Chemistry. New York: Dover, 1965.

波瓦里耶，让-皮埃尔。《拉瓦锡：化学家、生物学家、经济学家》。重印本。费城：宾夕法尼亚大学出版社，1998 年。

Poirier, Jean-Pierre. Lavoisier: Chemist, Biologist, Economist. Reprint. Philadelphia: University of Pennsylvania Press, 1998.

题词：Djerassi 和 Hoffmann，《氧气》，第 119 页。

epigraph: Djerassi and Hoffmann, Oxygen, p. 119.

当时的粒子加速器：多诺万，《安托万·拉瓦锡》，第 47 页。

the particle accelerator of its day: Donovan, Antoine Lavoisier, p. 47.

钻石燃烧实验在 Poirier 和Lavoisier 的著作第 58-60 页中有描述。

The diamond-burning experiment is described in Poirier, Lavoisier, pp. 58–60.

“物质中所含的空气”：Poirier，Lavoisier，第 58 页。

“the air contained in matter”: Poirier, Lavoisier, p. 58.

“樟脑溶于充分脱脂的酒精中”：朴茨茅斯收藏（Add. Ms. 3975），剑桥大学图书馆，剑桥大学，第 32-44 页。

“Camphire dissolved in well deflegmed spirit”: Portsmouth Collection (Add. Ms. 3975), Cambridge University Library, Cambridge University, pp. 32–44.

“土星中隐藏着不朽的灵魂”：手稿藏于耶鲁大学（贝内克图书馆，梅隆手稿79号），也可在牛顿项目网站上查阅。这段文字摘自乔治·斯塔基的《炼金术的精髓》（1654年）。关于炼金术术语的含义，我参考了印第安纳大学科学史学家威廉·纽曼在PBS网站“新星”节目“牛顿的黑暗秘密”中所做的分析。

“In [Saturn] is hid an immortal soul”: The manuscript is at Yale University (Beinecke Library, Mellon Ms. 79) and online at the Newton Project. The passage was copied from George Starkey’s The Marrow of Alchemy (1654). For the meaning of the alchemical terms, I relied on an analysis by William Newman, a historian of science at Indiana University, on the PBS Web site for the Nova show “Newton’s Dark Secrets.”

有关燃素假说的历史，请参阅 Stephen Finney Mason 的《科学史》，新修订版（纽约：Collier，1962 年），第 303-313 页。

For the history of the phlogiston hypothesis, see Stephen Finney Mason, A History of the Sciences, new rev. ed. (New York: Collier, 1962), pp. 303–13.

“受外力驱使”：Poirier，Lavoisier，第 63 页。

“impelled by forces”: Poirier, Lavoisier, p. 63.

“赋予地球上的分子以翅膀”：同上，第 62 页。

“gave wings to earthly molecules”: Ibid., p. 62.

拉瓦锡 1769 年的实验：同上，第 32-34 页。

Lavoisier’s 1769 experiment: Ibid., pp. 32–34.

拉瓦锡的婚姻：同上，第 39-41 页。

Lavoisier’s marriage: Ibid., pp. 39–41.

关于拉瓦锡的妻子及其在拉瓦锡实验中所扮演的角色，详见罗尔德·霍夫曼所著《拉瓦锡夫人》（“Mme. Lavoisier”），载于《美国科学家》杂志第90卷第1期（2002年1-2月），第22页。一个展示拉瓦锡作品的虚拟博物馆正在“拉瓦锡全景博物馆”（Panopticon Lavoisier）网站上筹建，其中包括他实验的详细年表以及部分实验设备的照片。此外，拉瓦锡的全部著作（法语版）也可在“拉瓦锡作品集”（Les Œuvres de Lavoisier）网站上查阅。

Details about Lavoisier’s wife and her role in his experiments are in Roald Hoffmann, “Mme. Lavoisier,” American Scientist 90, no. 1 (January–February 2002): 22. A virtual museum of Lavoisier’s work, including a detailed chronology of his experiments and photographs of some of his equipment, is being assembled online at Panopticon Lavoisier. In addition, the complete works of Lavoisier, in French, are available on the Web at Les Œuvres de Lavoisier.

“不同种类的空气”：普里斯特利撰写了三卷本著作《关于不同种类空气的实验和观察》（伦敦：J. Johnson 出版社，1774 年）。有关这部著作的简要历史，请参见梅森的《科学史》，第 304-306 页。

“different kinds of air”: Priestley wrote a three-volume work, Experiments and Observations on Different Kinds of Air (London: printed for J. Johnson, 1774). For a brief history of this work, see Mason’s History of the Sciences, pp. 304–6.

拉瓦锡对磷、硫、锡和密铁矿的实验：参见 Poirier, Lavoisier, pp. 65–66 和 Guerlac, Lavoisier, pp. 79–80。锡的实验在《科学史》第 308 页有描述。密铁矿实验中使用的装置称为气动槽，是斯蒂芬·黑尔斯设计的装置的一种变体。

Lavoisier’s experiments with phosphorus, sulfur, tin, and litharge: Poirier, Lavoisier, pp. 65–66, and Guerlac, Lavoisier, pp. 79–80. The tin experiment is described in History of the Sciences, p. 308. The apparatus in the litharge experiment, called a pneumatic trough, was a variation of one devised by Stephen Hales.

他认为自己知道答案：在磷和硫的实验中，他也观察到了空气吸收的迹象，一位巴黎化学家也报告了类似的结果。参见盖拉克，《拉瓦锡》，第79页。

He thought he knew the answer: In the experiments with phosphorus and sulfur he also saw signs of air absorption, and a Parisian chemist had reported a similar result. See Guerlac, Lavoisier, p. 79.

汞的价格估算来自 Poirier、Lavoisier，第 74 页。

Estimates of the price of mercurius calcinatus are from Poirier, Lavoisier, p. 74.

“无需添加”：同上。

“without addition”: Ibid.

“更令我惊讶的是”：同上。

“What surprised me more”: Ibid.

“我幻想我的乳房”：波里埃，拉瓦锡，第 76 页。

“I fancied that my breast”: Poirier, Lavoisier, p. 76.

拉瓦锡的首次汞实验在 Poirier, Lavoisier, pp. 79–80 中有描述。

Lavoisier’s first experiments with mercury are described in Poirier, Lavoisier, pp. 79–80.

“极佳的透气性”：同上，第103页。拉瓦锡在1775年4月向法兰西科学院发表的演讲中使用了这些词语，该演讲后来以《论煅烧过程中与金属结合并增加其重量的原理的性质》为题发表。三年后，他根据自己的新解释修订了该论文。詹姆斯·布莱恩特·科南特在《哈佛实验科学案例史》第一卷（马萨诸塞州剑桥：哈佛大学出版社，1957年）的《推翻燃素理论》一文中对这两个版本进行了比较。

“eminently breathable”: Ibid., p. 103. Lavoisier used these words in a talk to the French academy in April 1775 that was published as “On the Nature of the Principle Which Combines with Metals During Calcinations and Increases Their Weight.” Three years later, he revised the paper with his new interpretation. James Bryant Conant compared the two versions in “The Overthrow of the Phlogiston Theory,” in Harvard Case Histories in Experimental Science, vol. 1 (Cambridge, Mass.: Harvard University Press, 1957).

拉瓦锡于 1777 年 5 月 3 日向法国科学院报告了他用床垫进行的实验结果，题为“关于动物呼吸和空气通过肺部时发生的变化的实验”，后来又在他的《化学原理》第三章第 32-37 页中进行了阐述。

Lavoisier reported the results of his experiment with the matrass to the Académie des Sciences on May 3, 1777, as “Experiments on the Respiration of Animals and on the Changes Which Happen to Air in Its Passage Through Their Lungs,” and later in chapter 3 of his Elements of Chemistry, pp. 32–37.

“当锥子被插入时”：化学原理，第 35 页。

“when a taper was plunged”: Elements of Chemistry, p. 35.

“以耀眼的辉煌”：同上，第 36 页。

“with a dazzling splendor”: Ibid., p. 36.

“这是最完整的证明”：波里埃，拉瓦锡，第 104 页。

“Here is the most complete kind of proof”: Poirier, Lavoisier, p. 104.

拉瓦锡的处决：同上，第 381-382 页。

Lavoisier’s execution: Ibid., pp. 381–82.

一个在互联网上广为流传的故事：它显然起源于探索频道一档节目中的一段评论，在某些版本中，负责数眨眼次数的助手是拉格朗日。关于这个传说的辟谣，请参阅 William B. Jensen 的文章“拉瓦锡眨眼了吗？”，发表于《化学教育杂志》 81 (2004): 629。

A story ricocheting through the Internet: It apparently originated with a comment made on a Discovery Channel program, and in some versions the assistant counting the blinks was Lagrange. For a debunking of the legend, see William B. Jensen, “Did Lavoisier Blink?” Journal of Chemical Education 81 (2004): 629.

5.路易吉·加尔瓦尼：动物电力

5. Luigi Galvani: Animal Electricity

法拉，帕特里夏。《天使的娱乐：启蒙运动中的电力》。纽约：哥伦比亚大学出版社，2003 年。

Fara, Patricia. An Entertainment for Angels: Electricity in the Enlightenment. New York: Columbia University Press, 2003.

伽伐尼，路易吉。《伽伐尼论电与肌肉运动效应》。罗伯特·蒙特拉维尔·格林译。马萨诸塞州剑桥：E. Licht出版社，1953年。

Galvani, Luigi. Galvani Commentary of the Effect of Electricity and Muscular Motion. Translated by Robert Montraville Green. Cambridge, Mass.: E. Licht, 1953.

Heilbron, JL，《17 和 18 世纪的电力：早期现代物理学研究》。伯克利：加州大学出版社，1979 年。

Heilbron, J. L. Electricity in the 17th and 18th Centuries: A Study of Early Modern Physics. Berkeley: University of California Press, 1979.

奥斯特瓦尔德，威廉。《电化学：历史与理论》。新德里：Amerind出版社。为史密森学会和国家科学基金会出版，华盛顿特区，1980年。

Ostwald, Wilhelm. Electrochemistry: History and Theory. New Delhi: Amerind. Published for the Smithsonian Institution and the National Science Foundation, Washington, D.C., 1980.

潘卡尔迪，朱利亚诺。《伏特：启蒙时代的科学与文化》。普林斯顿，新泽西州：普林斯顿大学出版社，2005年。

Pancaldi, Giuliano. Volta: Science and Culture in the Age of Enlightenment. Princeton, N.J.: Princeton University Press, 2005.

佩拉，马塞洛。《模棱两可的青蛙：关于动物电的伽伐尼-伏特之争》。普林斯顿，新泽西州：普林斯顿大学出版社，1992年。

Pera, Marcello. The Ambiguous Frog: The Galvani-Volta Controversy on Animal Electricity. Princeton, N.J.: Princeton University Press, 1992.

题词：伽伐尼，《论电对肌肉运动的影响》，第40页。（除非另有说明，所有引文均出自罗伯特·蒙特拉维尔·格林的英文译本《伽伐尼论电对肌肉运动的影响》。）

epigraph: Galvani, De Viribus Electricitatis in Motu Musculari Commentarius, p. 40. (Unless otherwise indicated all quotations are from the English translation by Robert Montraville Green, Galvani Commentary on the Effect of Electricity and Muscular Motion.)

Symmer 的实验在 Heilbron 的《17 和 18 世纪的电力》第 431-37 页和 Pera 的《模棱两可的青蛙》第 38-39 页中有描述。

Symmer’s experiment is described in Heilbron, Electricity in the 17th and 18th Centuries, pp. 431–37, and in Pera, The Ambiguous Frog, pp. 38–39.

“当进行此实验时”：《暧昧的青蛙》，第 39 页，引自罗伯特·西默，“关于电的新实验和观察”，《哲学汇刊》 61 (1759)：340–89。

“When this experiment is performed”: The Ambiguous Frog, p. 39, quoting from Robert Symmer, “New Experiments and Observations Concerning Electricity,” Philosophical Transactions 61 (1759): 340–89.

十八世纪的电气风潮在《十七世纪和十八世纪的电力》（第 263-270 页）、《暧昧的青蛙》（第 3-18 页）和《法拉的天使娱乐》中均有描述。

The eighteenth-century electrical vogue is described in Electricity in the 17th and 18th Centuries, pp. 263–70; The Ambiguous Frog, pp. 3–18; and Fara, An Entertainment for Angels.

“据说源自某些动物”：《模棱两可的青蛙》，第 60-61 页，引用普里斯特利的《关于不同种类空气的实验和观察》，第 277-79 页。

“said to proceed from some animals”: The Ambiguous Frog, pp. 60–61, quoting Priestley’s Experiments and Observations on Different Kinds of Air, pp. 277–79.

伽伐尼在赞博尼宫附近进行的实验在《暧昧的青蛙》第 80 页中有描述。

Galvani’s experiment near the Palazzo Zamboni is described in The Ambiguous Frog, p. 80.

关于栏杆和银盒的实验：评论，第 40-41 页，以及模棱两可的青蛙，第 81-83 页。

The experiments with the railing and silver box: Commentary, pp. 40–41, and The Ambiguous Frog, pp. 81–83.

“悄悄地进入动物体内并不断积累”：评论，第 40 页。

“crept into the animal and accumulated”: Commentary, p. 40.

“就在脚触地的那一刻”：《暧昧的青蛙》，第 82 页。伽伐尼在《评注》第 43-44 页中描述了这一场景。

“At the very moment the foot touched”: The Ambiguous Frog, p. 82. Galvani describes the scene in Commentary, pp. 43–44.

伽伐尼的广泛推测见《评论》第 78-81 页。

Galvani’s wide-ranging speculations are in Commentary, pp. 78–81.

“但是，猜想也应该有个限度！”：同上，第 81 页。

“But let there be a limit to conjectures!”: Ibid., p. 81.

“在已证实的真理中”：《模棱两可的青蛙》，第 98 页。

“among the demonstrated truths”: The Ambiguous Frog, p. 98.

“同样的抽搐、痉挛和抽动”：同上，第 100 页。

“the same convulsions, spasms and jerks”: Ibid., p. 100.

伏特对锡和银夹子的实验：同上，第 105 页。

Volta’s experiment with tin and silver clips: Ibid., p. 105.

“伽伐尼的理论和解释”：同上，第 114 页。

“Galvani’s theory and explanations”: Ibid., p. 114.

“如果事情真是那样”：同上，第 113 页。

“If that is how things are”: Ibid., p. 113.

盖尔文主义者的实验挑战了伏特的双金属假说：同上，第 119-22 页。

the Galvanists’ experiments challenging Volta’s bimetallic hypothesis: Ibid., pp. 119–22.

“那么，为什么要归因于”：同上，第 122 页。

“Why then ascribe”: Ibid., p. 122.

“每次我触摸它”：同上，第 123 页。

“Each time I touch it”: Ibid., p. 123.

伽伐尼没有外部导体的实验（通常被称为他的“第三个实验”）：同上，第 129 页。

Galvani’s experiment without external conductors (often referred to as his “third experiment”): Ibid., p. 129.

“但如果事情就是这样”：《模棱两可的青蛙》，第 13 页。

“But if that is how things are”: The Ambiguous Frog, p. 13.

伏特电池：见同书，第 153-158 页。

Volta’s battery: described in ibid., pp. 153–58.

伽伐尼的最后一个（“第四个”）实验：同上，第 147-148 页。

Galvani’s final (“fourth”) experiment: Ibid., pp. 147–48.

“现在有什么不同之处”：同上，第 148 页。

“Now what dissimilarity”: Ibid., p. 148.

6.迈克尔·法拉第：《深藏的秘密》

6. Michael Faraday: Something Deeply Hidden

坎托尔，杰弗里。《迈克尔·法拉第：桑德曼主义者和科学家》。新版。伦敦：帕尔格雷夫·麦克米伦出版社，1993年。

Cantor, Geoffrey. Michael Faraday, Sandemanian and Scientist. New ed. London: Palgrave Macmillan, 1993.

迪布纳，伯恩。《奥斯特与电磁学的发现》。康涅狄格州诺沃克：伯恩迪图书馆，1961年。

Dibner, Bern. Oersted and the Discovery of Electromagnetism. Norwalk, Conn.: Burndy Library, 1961.

法拉第，迈克尔。《蜡烛的化学史》。纽约：多佛出版社，2003 年；原版出版于 1861 年。

Faraday, Michael. The Chemical History of a Candle. New York: Dover, 2003; originally published 1861.

———. 《电学实验研究》。纽约：多佛出版社，1965 年；原出版于 1839–1855 年。

———. Experimental Researches in Electricity. New York: Dover, 1965; originally published 1839–1855.

——。《物质的力量》。伟大思想家系列。纽约州布法罗：普罗米修斯出版社，1993年。

———. The Forces of Matter. Great Minds Series. Buffalo, N.Y.: Prometheus, 1993.

法拉第，迈克尔，和霍华德·J·费舍尔。《法拉第电学实验研究：初读指南》。圣达菲，新墨西哥州：绿狮出版社，2001年。

Faraday, Michael, and Howard J. Fisher. Faraday’s Experimental Researches in Electricity: Guide to a First Reading. Santa Fe, N.M.: Green Lion, 2001.

法拉第，迈克尔，和托马斯·马丁。《法拉第日记》。伦敦：贝尔出版社，1932年。

Faraday, Michael, and Thomas Martin. Faraday’s Diary. London: Bell, 1932.

汉密尔顿，詹姆斯。《发现的一生：迈克尔·法拉第，科学革命的巨人》。纽约：兰登书屋，2004年。

Hamilton, James. A Life of Discovery: Michael Faraday, Giant of the Scientific Revolution. New York: Random House, 2004.

琼斯，本斯。《法拉第的生平与书信》。伦敦：朗文出版社，1870年。

Jones, Bence. The Life and Letters of Faraday. London: Longmans, Green, 1870.

莱尔斯，恩斯特。《精神科学：电与迈克尔·法拉第》。伦敦：鲁道夫·施泰纳出版社，1975年。

Lehrs, Ernst. Spiritual Science: Electricity and Michael Faraday. London: Rudolph Steiner Press, 1975.

Russell, Colin Archibald. Michael Faraday: Physics and Faith. New York: Oxford University Press, 2000.

威廉姆斯，L.皮尔斯。《迈克尔·法拉第传》。纽约：达卡波出版社，1987年。

Williams, L. Pearce. Michael Faraday: A Biography. New York: Da Capo, 1987.

伍利，本杰明。《科学的新娘：浪漫、理性与拜伦的女儿》。纽约：麦格劳-希尔出版社，2000年。

Woolley, Benjamin. The Bride of Science: Romance, Reason, and Byron’s Daughter. New York: McGraw-Hill, 2000.

第一段题词：琼斯，《法拉第的生平与书信》，第 2 卷，第 473-74 页。琼斯将这封信的日期定为 1867 年 4 月 22 日。

first epigraph: Jones, The Life and Letters of Faraday, vol. 2, pp. 473–74. Jones dates the letter April 22, 1867.

第二段题词：法拉第，《电学实验研究》，第三辑，第 280 段。

second epigraph: Faraday, Experimental Researches in Electricity, Third Series, para. 280.

“数字的女巫”：伍利，《科学的新娘》，第 274 页。

“Enchantress of Numbers”: Woolley, The Bride of Science, p. 274.

《科学新娘》：同上，第 306 页。

“Bride of Science”: Ibid., p. 306.

“神经系统的演算”：同上，第 305 页。

“calculus of the nervous system”: Ibid., p. 305.

“仙女”：汉密尔顿，《发现的一生》，第 318 页。

“ladye-fairy”: Hamilton, A Life of Discovery, p. 318.

奥斯特在《关于电流对磁针的影响的实验》一文中描述了他的发现，该文发表于《哲学年鉴》 16 (1820): 276。

Oersted described his discovery in “Experiments on the Effect of a Current of Electricity on the Magnetic Needle,” Annals of Philosophy 16 (1820): 276.

法拉第用简易电动机进行的实验在《法拉第日记》第 50-51 页中有描述，并在威廉姆斯所著的《迈克尔·法拉第》第 156 页和《发现的一生》第 164-165 页中有总结。

Faraday’s experiments with a crude electric motor are described in Faraday’s Diary, pp. 50–51, and are summarized in Williams, Michael Faraday, p. 156, and A Life of Discovery, pp. 164–65.

工业时代的差事：发现的一生，第 151-156 页。

errands of the Industrial Age: A Life of Discovery, pp. 151–56.

“不幸被占用”：威廉姆斯，迈克尔·法拉第，第 109 页。

“unfortunately occupied”: Williams, Michael Faraday, p. 109.

紧张局势：同上，第 177-178 页。

crispations: Ibid., pp. 177–78.

“锡板上的水银”：发现的一生，第 236-37 页，引用了法拉第的日记。

“Mercury on tin plate”: A Life of Discovery, pp. 236–37, quoting Faraday’s diaries.

感应环实验在威廉姆斯所著的《迈克尔·法拉第》第 182-183 页、法拉第日记（1831 年 8 月 29 日）第 367 页以及《电学实验研究》第一辑第 27-28 段中均有描述。

The induction ring experiment is described in Williams, Michael Faraday, pp. 182–83; in Faraday’s Diary, August 29, 1831, p. 367; and in Experimental Researches in Electricity, First Series, para. 27–28.

“电波”：威廉姆斯，迈克尔·法拉第，第 183 页。

“wave of electricity”: Williams, Michael Faraday, p. 183.

正如一位德国科学家所提出的：这是约翰·里特，同上，第 228-30 页。

as a German scientist proposed: This was Johann Ritter, ibid., pp. 228–30.

法拉第的崩溃：发现的一生，第 293-94 页。

Faraday’s breakdown: A Life of Discovery, pp. 293–94.

“你让我感到绝望”：同上，第 319 页。

“You drive me to desperation”: Ibid., p. 319.

也许这是个过于牵强的猜测：进行极化实验的另一个灵感可能来自威廉·汤姆逊（未来的开尔文勋爵）的一封信：威廉姆斯，迈克尔·法拉第，第 383-84 页。

Maybe it is too great a reach: Another inspiration for undertaking the polarization experiment may have been a letter from William Thomson, the future Lord Kelvin: Williams, Michael Faraday, pp. 383–84.

一个一直困扰着他的问题：法拉第在 1822 年 9 月 10 日的日记第 71 页中描述了他早先使用电解质槽的尝试。

a question that had been gnawing at him: Faraday describes an earlier attempt using a trough of electrolytes in his diary entry for September 10, 1822, p. 71.

“以便他们能够进行监管”：摘自三一之家网站上发布的官方历史。

“so that they might regulate”: From the official history posted on the Trinity House Web site.

法拉第在灯塔中的工作：发现的一生，第 322-23 页。

Faraday’s work in lighthouses: A Life of Discovery, pp. 322–23.

法拉第在他的日记第 4 卷第 256-267 段和第十九系列实验研究第 2146-2172页中描述了他的光束实验。威廉姆斯所著的《迈克尔·法拉第》第 384-387 页也有相关记载。

Faraday describes his experiments with light beams in vol. 4 of his diary, paragraphs 256–67, and in the Nineteenth Series of Experimental Researches, 2146–72. There is also an account in Williams, Michael Faraday, pp. 384–87.

“目前我几乎没有片刻空闲”：《发现的一生》，第 327 页。

“At present I have scarcely a moment”: A Life of Discovery, p. 327.

“但是当磁极相反时”：威廉姆斯，迈克尔·法拉第，第 386 页。托马斯·马丁编辑的 1932 年版日记中包含带有三重下划线的手写页面的传真件。

“BUT when contrary magnetic poles”: Williams, Michael Faraday, p. 386. The 1932 edition of the diary, edited by Thomas Martin, includes a facsimile of the handwritten page with the triple underscoring.

“这一切都是一场梦”：探索的一生，第 334 页。

“ALL THIS IS A DREAM”: A Life of Discovery, p. 334.

“你看看你做了什么”：同上，第 320 页。

“You see what you do”: Ibid., p. 320.

7.詹姆斯·焦耳：《世界是如何运转的》

7. James Joule: How the World Works

拜尔，汉斯·克里斯蒂安·冯。《麦克斯韦妖：为什么温暖消散，时间流逝》。纽约：兰登书屋，1999年。

Baeyer, Hans Christian von. Maxwell’s Demon: Why Warmth Disperses and Time Passes. New York: Random House, 1999.

Caneva, Kenneth L. Robert Mayer 与能量守恒。普林斯顿，新泽西州：普林斯顿大学出版社，1993 年。

Caneva, Kenneth L. Robert Mayer and the Conservation of Energy. Princeton, N.J.: Princeton University Press, 1993.

Cardwell, Donald SL从瓦特到克劳修斯：早期工业时代热力学的兴起。伦敦：海涅曼出版社，1971 年。

Cardwell, Donald S. L. From Watt to Clausius: The Rise of Thermodynamics in the Early Industrial Age. London: Heinemann, 1971.

——.詹姆斯·焦耳传。英国曼彻斯特：曼彻斯特大学出版社，1991年。

———. James Joule: A Biography. Manchester, England: Manchester University Press, 1991.

——. 《车轮、时钟和火箭：技术史》。纽约：诺顿出版社，2001年。

———. Wheels, Clocks, and Rockets: A History of Technology. New York: Norton, 2001.

卡诺，萨迪。《论火的动力：以及其他关于热力学第二定律的论文》。纽约：多佛出版社，2005年。

Carnot, Sadi. Reflections on the Motive Power of Fire: And Other Papers on the Second Law of Thermodynamics. New York: Dover, 2005.

焦耳、詹姆斯·普雷斯科特、威廉·斯科尔斯比、里昂·普莱费尔和威廉·汤姆逊。《詹姆斯·普雷斯科特·焦耳的科学论文集》。伦敦：学会，1963 年；原出版于 1887 年。

Joule, James Prescott, William Scoresby, Lyon Playfair, and William Thomson. The Scientific Papers of James Prescott Joule. London: The Society, 1963; originally published 1887.

林德利，大卫。《开尔文度数：天才、发明与悲剧的故事》。华盛顿特区：约瑟夫·亨利出版社，2005年。

Lindley, David. Degrees Kelvin: A Tale of Genius, Invention, and Tragedy. Washington, D.C.: Joseph Henry Press, 2005.

汤普森，西尔瓦努斯·菲利普斯。《开尔文勋爵传》。第2版。纽约：切尔西出版社，1977年；原版出版于1910年。

Thompson, Silvanus Phillips. The Life of Lord Kelvin. 2nd ed. New York: Chelsea, 1977; originally published 1910.

Truesdell, Clifford A.热力学的悲喜剧史，1822–1854。纽约：Springer，1980。

Truesdell, Clifford A. The Tragicomical History of Thermodynamics, 1822–1854. New York: Springer, 1980.

题词：Truesdell，《热力学的悲喜剧史》，第 164-165 页。

epigraph: Truesdell, The Tragicomical History of Thermodynamics, pp. 164–65.

“接种了法拉第火”：汤普森，《开尔文勋爵传》，第 19 页。

“inoculated with Faraday fire”: Thompson, The Life of Lord Kelvin, p. 19.

在《开尔文勋爵传》第 265 页和《詹姆斯·焦耳》第 88-89 页中，都描述了在小径上与开尔文的相遇。

The encounter on the trail with Kelvin is described in Life of Lord Kelvin, p. 265, and in Cardwell, James Joule, pp. 88–89.

焦耳和汤姆逊在牛津的会面：詹姆斯·焦耳，第 82-83 页，以及林德利，《开尔文度数》，第 74-75 页。

Joule and Thomson’s meeting in Oxford: James Joule, pp. 82–83, and Lindley, Degrees Kelvin, pp. 74–75.

“焦耳是，我确信”：詹姆斯·焦耳，第 85 页。

“Joule is, I am sure”: James Joule, p. 85.

鲁姆福德与拉瓦锡夫人的婚姻在波瓦里埃的《拉瓦锡传》第407-409页中有记载（我在第四章的笔记中引用了该书）。波瓦里埃还在第125-126页描述了她与经济学家皮埃尔·萨缪尔·杜邦·德·内穆尔（化学公司创始人的父亲）的婚外情。

The marriage of Rumford to Mme. Lavoisier is recounted in Poirier, Lavoisier, pp. 407–9 (cited in my notes for chapter 4). Poirier also describes, pp. 125–26, an extramarital affair she had with the economist Pierre Samuel du Pont de Nemours, father of the founder of the chemical company.

“信誉良好”：同上，第 407 页。

“en bon point”: Ibid., p. 407.

“仅仅依靠强度”：本杰明·汤普森，“关于摩擦生热的来源的研究”，皇家学会哲学汇刊88 (1798): 80–102；摘自马吉的《物理学资料汇编》（在我的第 3 章笔记中引用），第 159–60 页。

“merely by the strength”: Benjamin Thompson, “An Inquiry Concerning the Source of the Heat Which Is Excited by Friction,” Philosophical Transactions of the Royal Society 88 (1798): 80–102; excerpted in Magie’s A Source Book in Physics (cited in my notes for chapter 3), pp. 159–60.

“非常迅速而激烈的骚动”：胡克，《显微图谱》观察 VI，“关于小玻璃棒”（在我的第 3 章笔记中引用），第 12 页。

“a very brisk and vehement agitation”: Hooke, Micrographia. Observ. VI. “Of Small Glass Canes” (cited in my notes for chapter 3), p. 12.

焦耳令人震惊的童年实验和其他传记细节出自詹姆斯·焦耳，第 13-16 页。

Joule’s shocking childhood experiments and other biographical details are from James Joule, pp. 13–16.

“我几乎无法怀疑电磁学”：詹姆斯·普雷斯科特·焦耳的科学论文集，第 1 卷，第 14 页。

“I can hardly doubt that electro-magnetism”: The Scientific Papers of James Prescott Joule, vol. 1, p. 14.

“似乎没有什么可以阻止的”：同上，第 47 页；詹姆斯·焦耳，第 36 页。

“there seemed to be nothing to prevent”: Ibid., p. 47; James Joule, p. 36.

焦耳马达的描述见《科学论文集》第 1 卷第 1-3 页、第 16-17 页，以及詹姆斯·焦耳的著作第 32-37 页。

Joule’s motors are described in Scientific Papers, vol. 1, pp. 1–3, 16–17, and in James Joule, pp. 32–37.

“这种比较非常不利”：詹姆斯·焦耳，第 37 页，引自 1841 年 2 月 16 日在皇家维多利亚画廊发表的公开演讲。

“The comparison is so very unfavourable”: James Joule, p. 37, quoting a public lecture at the Royal Victoria Gallery, February 16, 1841.

焦耳在《焦耳科学论文集》第 1 卷第 123-159 页中报告了他用曲柄进行的实验，题为“论磁电的热效应和热的机械价值” ；另见詹姆斯·焦耳，第 53-56 页。

Joule reported on his experiment with the crank in part 1 of Joule, “On the Calorific Effects of Magneto-Electricity, and on the Mechanical Value of Heat,” Scientific Papers, vol. 1, pp. 123–59; see also James Joule, pp. 53–56.

关于滑轮实验的内容见《热效应》第二部分，第 149-157 页，以及詹姆斯·焦耳的著作，第 56-58 页。

The experiment with the pulleys is in part 2 of “Calorific Effects,” pp. 149–57, and in James Joule, pp. 56–58.

“该主题没有引起兴趣”：科学论文，第 2 卷，第 215 页。

“the subject did not excite”: Scientific Papers, vol. 2, p. 215.

焦耳在牛津大学发表的实验成果题为“论流体摩擦产生的热量所确定的热机械当量”，发表于《科学论文集》第 2 卷，第 277-281 页。后续的改进见题为“论热机械当量”的论文，发表于《科学论文集》第 1 卷，第 298-328 页。

Joule published the experiment presented at Oxford as “On the Mechanical Equivalent of Heat, as Determined by the Heat Evolved by the Friction of Fluids,” Scientific Papers, vol. 2, pp. 277–81. For later refinements see the similarly titled “On the Mechanical Equivalent of Heat,” Scientific Papers, vol. 1, pp. 298–328.

“无可挽回地失去”：《开尔文勋爵传》，第 288 页。

“irrecoverably lost”: Life of Lord Kelvin, p. 288.

“在过去的有限时间内”：同上，第 291 页。

“Within a finite period of time past”: Ibid., p. 291.

8. AA·米歇尔森：《迷失太空》

8. A. A. Michelson: Lost in Space

利文斯顿，多萝西·米歇尔森。《光之大师：阿尔伯特·A·米歇尔森传》。重印版。芝加哥：芝加哥大学出版社，1979年。

Livingston, Dorothy Michelson. Master of Light: A Biography of Albert A. Michelson. Reprint. Chicago: University of Chicago Press, 1979.

马赫，恩斯特。《物理光学原理：历史与哲学论述》。约翰·S·安德森和A·F·A·杨译。伦敦：梅休恩出版社，1926年；原版出版于1921年。

Mach, Ernst. The Principles of Physical Optics: An Historical and Philosophical Treatment. Translated by John S. Anderson and A. F. A. Young. London: Methuen, 1926; originally published 1921.

麦克斯韦，詹姆斯·克拉克。《物质与运动》。纽约：多佛出版社，1952 年；原版出版于 1876 年。

Maxwell, James Clerk. Matter and Motion. New York: Dover, 1952; originally published 1876.

迈克尔逊，阿尔伯特·亚伯拉罕。《光速的实验测定》。明尼阿波利斯：隆德出版社，1964 年。本书是迈克尔逊 1878 年实验的手写报告的复制品，由霍尼韦尔公司委托撰写。

Michelson, Albert Abraham. Experimental Determination of the Velocity of Light. Minneapolis: Lund, 1964. A reproduction of Michelson’s handwritten report on his experiments of 1878, commissioned by Honeywell, Inc.

——。《光波及其用途》。芝加哥：芝加哥大学出版社，1961年；原版出版于1903年。

———. Light Waves and Their Uses. Chicago: University of Chicago Press, 1961; originally published 1903.

———.光学研究。凤凰科学系列。芝加哥：芝加哥大学出版社，1962 年；原版出版于 1927 年。

———. Studies in Optics. Phoenix Science Series. Chicago: University of Chicago Press, 1962; originally published 1927.

Swenson, Lloyd S.以太：迈克尔逊-莫雷-米勒以太漂移实验的历史，1880–1930 年。奥斯汀：德克萨斯大学出版社，1972 年。

Swenson, Lloyd S. Ethereal Aether: A History of the Michelson-Morley-Miller Aether-Drift Experiments, 1880–1930. Austin: University of Texas Press, 1972.

题词：麦克斯韦，《物质与运动》，引自斯文森，《以太》，第 30 页。

epigraph: Maxwell, Matter and Motion, quoted in Swenson, Ethereal Aether, p. 30.

米歇尔森崩溃了：利文斯顿，《光之大师》，第 111-115 页。

Michelson’s breakdown: Livingston, Master of Light, pp. 111–15.

“脑子有点软”：莫利在1885年9月27日写给父亲的一封信中提到“一些症状表明他的大脑出现了软化”。引自《光明大师》，第112页。

“soft in the head”: In a letter to his father, September 27, 1885, Morley referred to “some symptoms which point to softening of the brain.” Quoted in Master of Light, p. 112.

“展现所有幻想、情绪和情感”：迈克尔逊，《光波及其用途》，第 2 页。

“rendering all the fancies, moods, and emotions”: Michelson, Light Waves and Their Uses, p. 2.

伽利略关于光速的实验：两门新科学（在第 1 章的注释中引用），Opere，第 88 页。

Galileo’s experiment on the speed of light: Two New Sciences (cited in the notes for chapter 1), Opere, p. 88.

“如果不是瞬间的”：同上。

“if not instantaneous”: Ibid.

光速测量的早期历史：光之大师，第 47-49 页，以及 Norriss S. Hetherington，“光速”，载于 JL Heilbron 编，《牛津现代科学史指南》（纽约：牛津大学出版社，2003 年），第 467-468 页。

early history of light-speed measurements: Master of Light, pp. 47–49, and Norriss S. Hetherington, “Speed of Light,” in J. L. Heilbron, ed., The Oxford Companion to the History of Modern Science (New York: Oxford University Press, 2003), pp. 467–68.

罗默关于光速的论文被翻译成英文，题为《关于光运动的论证》，发表于《皇家学会哲学汇刊》第12卷（1677年6月25日），第893-894页。布拉德利在《关于恒星新发现的运动的论述》，发表于《皇家学会哲学汇刊》第35卷（1727-1728年），第637-661页，描述了恒星光行差。这两篇论文都可以在马吉的《物理学资料汇编》 （第三章注释中引用）第335-340页找到。他们估算的实际数值会因所依据的行星距离数据（当时或现在）而有所不同。我使用了《不列颠百科全书》中罗默和布拉德利条目中的数据。

Roemer’s paper on the speed of light was translated into English as “A Demonstration Concerning the Motion of Light,” Philosophical Transactions of the Royal Society 12 (June 25, 1677): 893–94. Bradley described stellar aberration in “An Account of a New Discovered Motion of the Fixed Stars,” Philosophical Transactions of the Royal Society 35 (1727–28): 637–61. Both can be found in Magie’s A Source Book in Physics (cited in the notes for chapter 3), pp. 335–40. The actual values of their estimates vary depending on whether they are based on what was known then or now about planetary distances. I used the numbers in the Encyclopaedia Britannica entries for Roemer and Bradley.

斐索的实验发表为“Sur un expériencerelative à la vitesse de propagation de la lumié”，Comptes Rendus 29 (1849): 90。英文翻译见《物理学原始资料》，第 341-42 页。

Fizeau’s experiment appeared as “Sur un expérience relative à la vitesse de propagation de la lumiére,” Comptes Rendus 29 (1849): 90. An English translation is in Source Book in Physics, pp. 341–42.

福柯在《光速的实验测定：太阳视差》一文中描述了他的实验，该文发表于《法国科学院院刊》55 (1862): 501–3, 792–96，摘录于《物理学资料汇编》第 343–44 页。

Foucault described his experiment in “Détermination expérimentale de la vitesse de la lumière: parallaxe du Soleil,” Comptes Rendus 55 (1862): 501–3, 792–96, which is excerpted in Source Book in Physics, pp. 343–44.

米歇尔森的早期传记历史出自《以太》第 33-43 页和《光之大师》第 11-44 页。

Michelson’s early biographical history is from Ethereal Aether, pp. 33–43, and Master of Light, pp. 11–44.

迈克尔逊在《光速的实验测定》（载于《美国科学促进会会刊》第27卷（1878年），第71-77页）中描述了他的光速实验。有关概述，请参见《光之大师》（第51-63页）。他的原始手稿于1964年由霍尼韦尔公司以影印本的形式重印出版。

Michelson describes his light-speed experiment in “Experimental Determination of the Velocity of Light,” Proceedings AAAS, vol. 27 (1878), pp. 71–77. For a summary see Master of Light, pp. 51–63. His original handwritten paper was reprinted and published as a facsimile by Honeywell in 1964.

“大约是光速的 200 倍”：光速，第 5 页。

“being about 200 times that”: Velocity of Light, p. 5.

“看来科学界”：光之大师，第 63 页。

“It would seem that the scientific world”: Master of Light, p. 63.

“球状体”和“用斜拍击打的网球”：牛顿在《关于光和颜色的理论》中使用了这些词语，该理论在第 3 章的注释中引用。

“globular bodyes” and “a Tennis-ball struck with an oblique Racket”: Newton used these words in “A Theory Concerning Light and Colors,” cited in the notes for chapter 3.

“轻松的思考”：牛顿在他的《光学》；或，光的反射、折射、弯曲和颜色的论述，第二版，附增补（伦敦：1717 年），第三卷，第一部分，第 323 页中使用了该术语。

“fits of easy reflexion”: Newton uses the term in his Opticks; or, A Treatise of the Reflections, Refractions, Inflexions and Colours of Light, 2nd ed., with additions (London: 1717), 3rd book, part 1, p. 323.

《以太》第 67-68 页描述了欧洲之旅。根据《光之大师》第 74-75 页的记载，米歇尔森于 1881 年先去了柏林，然后去了巴黎。

The trip to Europe is described in Ethereal Aether, pp. 67–68. According to Master of Light, pp. 74–75, Michelson goes to Berlin first and then to Paris in 1881.

“逆流而上，奋力前行”：《光明大师》，第 77 页。

“struggling upstream and back”: Master of Light, p. 77.

迈克尔逊的柏林和波茨坦实验：迈克尔逊，“地球和发光以太的相对运动”，《美国科学杂志》，第三辑，22（8 月）：120-29。在《以太》第 68-73 页和《光之大师》第 77-84 页中有所描述。

Michelson’s Berlin and Potsdam experiments: Michelson, “The Relative Motion of the Earth and the Luminiferous Aether,” American Journal of Science, Third Series, 22 (August): 120–29. Described in Ethereal Aether, pp. 68–73, and Master of Light, pp. 77–84.

“极其敏感”：阿尔伯特·A·迈克尔逊和爱德华·W·莫利，《论地球和发光以太的相对运动》，《美国科学杂志》，第三辑，第34卷，第203期（1887年11月），第124页。他所指的事件发生在波茨坦。

“So extraordinarily sensitive”: Albert A. Michelson and Edward W. Morley, “On the Relative Motion of the Earth and the Luminiferous Ether,” American Journal of Science, Third Series, vol. 34, no. 203 (November 1887), p. 124. The event he refers to took place in Potsdam.

“我非常尊敬他”：贝尔在 1883 年写给妻子的一封信中表达了这一观点，该信被引自《光明大师》第 96-97 页。

“I have a very high respect”: Bell made the observation in 1883 in a letter to his wife quoted in Master of Light, pp. 96–97.

测量真空中的光速：同上，第 95-96 页。

measuring light speed in a vacuum: Ibid., pp. 95–96.

重复菲佐实验：《以太》第 81-87 页，《光之大师》第 110-111 页。

repeating the Fizeau experiment: Ethereal Aether, pp. 81–87, and Master of Light, pp. 110–11.

Case 的火灾：光明大师，第 121-22 页。

the fire at Case: Master of Light, pp. 121–22.

“如果光以相同的速度传播”：莫雷在 1887 年 4 月 17 日写给他父亲的一封信中这样写道；引自《以太》第 91 页。

“if light travels with the same velocity”: Morely wrote this in a letter of April 17, 1887, to his father; quoted in Ethereal Aether, p. 91.

迈克尔逊-莫雷实验：“相对运动”，总结于《以太》第 91-97 页和《光之大师》第 126-133 页。

the Michelson-Morley experiment: “The Relative Motion,” summarized in Ethereal Aether, pp. 91–97, and Master of Light, pp. 126–33.

米勒在威尔逊山：以太，第 205-206 页。

Miller on Mount Wilson: Ethereal Aether, pp. 205–6.

米歇尔森论威尔逊山：同上，第 225-226 页。

Michelson on Mount Wilson: Ibid., pp. 225–26.

“最宏大的概括之一”：光波及其用途，第 162 页。

“one of the grandest generalizations”: Light Waves and Their Uses, p. 162.

爱因斯坦的狭义相对论的发表改变了这一切：然而，爱因斯坦否认迈克尔逊-莫雷实验的结果本身是他进行研究的动机。

It took the publication of Einstein’s special theory: Einstein, however, denied that the Michelson-Morley results were in themselves a motivation for his work.

9.伊万·巴甫洛夫：《测量不可测量之物》

9. Ivan Pavlov: Measuring the Immeasurable

巴布金，BP巴甫洛夫。芝加哥：芝加哥大学出版社，1975 年。

Babkin, B. P. Pavlov. Chicago: University of Chicago Press, 1975.

弗洛洛夫，YP，《巴甫洛夫和他的学派：条件反射理论》。纽约：约翰逊重印本，1970年。

Frolov, Y. P. Pavlov and His School: The Theory of Conditioned Reflexes. New York: Johnson Reprint, 1970.

Gray, Jeffrey A.伊万·巴甫洛夫。纽约：维京出版社，1980 年。

Gray, Jeffrey A. Ivan Pavlov. New York: Viking, 1980.

詹姆斯，威廉。《心理学原理》。纽约：多佛出版社，1950 年；原版出版于 1890 年。

James, William. The Principles of Psychology. New York: Dover, 1950; originally published 1890.

巴甫洛夫，伊万·彼得罗维奇。《条件反射：大脑皮层生理活动的研究》。G.V.安雷普译。纽约：多佛出版社，1960年；原版出版于1927年。

Pavlov, Ivan Petrovich. Conditioned Reflexes: An Investigation of the Physiological Activity of the Cerebral Cortex. Translated by G. V. Anrep. New York: Dover, 1960; originally published 1927.

———.条件反射讲义。第 1 卷。W. Horsley Gantt 译。纽约：国际出版社，1928 年；原版出版于 1923 年。

———. Lectures on Conditioned Reflexes. Vol. 1. Translated by W. Horsley Gantt. New York: International, 1928; originally published 1923.

谢切诺夫，伊万。大脑的反射。马萨诸塞州剑桥：麻省理工学院出版社，1965 年。

Sechenov, Ivan. Reflexes of the Brain. Cambridge, Mass.: MIT Press, 1965.

托德斯，丹尼尔·菲利普。《伊万·巴甫洛夫：探索动物机器》。纽约：牛津大学出版社，2000 年。

Todes, Daniel Philip. Ivan Pavlov: Exploring the Animal Machine. New York: Oxford University Press, 2000.

——.巴甫洛夫的生理工厂：实验、解释、实验室事业。巴尔的摩：约翰·霍普金斯大学出版社，2002年。

———. Pavlov’s Physiology Factory: Experiment, Interpretation, Laboratory Enterprise. Baltimore: Johns Hopkins University Press, 2002.

题词：托德斯，《巴甫洛夫的生理工厂》，第 123 页，引用巴甫洛夫 1893 年的论文《活体解剖》。

epigraph: Todes, Pavlov’s Physiology Factory, p. 123, quoting Pavlov’s 1893 essay, “Vivisection.”

巴甫洛夫的一些狗的名字可以在蒂姆·塔利的《巴甫洛夫的狗》（《当代生物学》 13，第 4 期：R117-19）以及冷泉港实验室网站的页面上找到。

The names of some of Pavlov’s dogs are in Tim Tully, “Pavlov’s Dogs” (Current Biology 13, no. 4: R117–19), and on a page at the Web site for Cold Spring Harbor Laboratory.

“当我解剖和摧毁时”：巴布金，《巴甫洛夫》，第 162 页。

“When I dissect and destroy”: Babkin, Pavlov, p. 162.

巴甫洛夫生平的细节来自他的同事兼翻译家 W. Horsley Gantt 在巴甫洛夫《条件反射讲义》第 11-31 页、巴甫洛夫《条件反射讲义》第 5-23 页以及 Todes 所著《伊万·巴甫洛夫》第 11-43 页中的传记草稿。

Details of Pavlov’s life are from a biographical sketch by his colleague and translator W. Horsley Gantt in Pavlov, Lectures on Conditioned Reflexes, pp. 11–31; Pavlov, pp. 5–23; and Todes, Ivan Pavlov, pp. 11–43.

巴甫洛夫和图书馆：托德斯，《伊万·巴甫洛夫》，第 19 页。

Pavlov and the library: Todes, Ivan Pavlov, p. 19.

“绝对所有特性”：谢切诺夫，《大脑的反射》，第 4 页。

“Absolutely all the properties”: Sechenov, Reflexes of the Brain, p. 4.

“复杂的化学工厂”：托德斯，《伊万·巴甫洛夫》，第 59 页。

“complex chemical factory”: Todes, Ivan Pavlov, p. 59.

巴甫洛夫的消化实验：Todes，Ivan Pavlov，第 53–65 页；巴甫洛夫，第 224-30 页；伊万·巴甫洛夫·格雷 (Gray) ，第 20-25 页。

Pavlov’s digestive experiments: Todes, Ivan Pavlov, pp. 53–65; Pavlov, pp. 224–30; and Gray, Ivan Pavlov, pp. 20–25.

“每一个物质系统”：巴甫洛夫，《条件反射》，第 1 讲，第 8 页。

“Every material system”: Pavlov, Conditioned Reflexes, lecture 1, p. 8.

他差点就失去了这项荣誉：有关诺贝尔奖政治的精彩描述，请参阅《巴甫洛夫的生理工厂》，第 332-45 页。

an honor he was almost denied: For a fascinating account of the Nobel politicking, see Pavlov’s Physiology Factory, pp. 332–45.

“很明显，我们没有”：巴甫洛夫，第 229 页。

“It is clear that we did not”: Pavlov, p. 229.

巴甫洛夫关于唾液分泌实验的第一手资料可以在他的两本书《条件反射》和《条件反射讲义》第 1 卷中找到。良好的二手资料有 Gray，《伊万·巴甫洛夫》，第 26-51 页，以及 Todes，《伊万·巴甫洛夫》，第 71-79 页。

Pavlov’s firsthand accounts of his salivation experiments can be found in his two books, Conditioned Reflexes and Lectures on Conditioned Reflexes, vol. 1. Good secondary sources are Gray, Ivan Pavlov, pp. 26–51, and Todes, Ivan Pavlov, pp. 71–79.

“确信其无用性”：条件反射讲义，第 71 页。

“convinced of the uselessness”: Lectures on Conditioned Reflexes, p. 71.

“我们究竟有什么手段呢？”巴甫洛夫，第 277 页。

“Indeed, what means have we”: Pavlov, p. 277.

“难道没有永恒的悲伤吗？”：条件反射讲义，第 50 页。

“Does not the eternal sorrow”: Lectures on Conditioned Reflexes, p. 50.

“但现在生理学家转变了”：同上，第 121 页。

“But now the physiologist turns”: Ibid., p. 121.

“同样的原子”：詹姆斯，《心理学原理》，第 146 页。

“The self-same atoms”: James, The Principles of Psychology, p. 146.

“原始心灵尘埃”：同上，第 150 页。

“primordial mind-dust”: Ibid., p. 150.

“就像物质原子一样”：同上，第 149 页。

“Just as the material atoms”: Ibid., p. 149.

“灵魂是相关的”：同上，第 131 页。

“The soul stands related”: Ibid., p. 131.

本杰明·利贝特在《心灵时间：意识中的时间因素》（马萨诸塞州剑桥：哈佛大学出版社，2004 年）一书中描述了他对自由意志的实验。

Benjamin Libet describes his experiments on free will in Mind Time: The Temporal Factor in Consciousness (Cambridge, Mass.: Harvard University Press, 2004).

“如果我们彻底了解”：心理学原理，第 132-133 页。

“If we knew thoroughly”: Principles of Psychology, pp. 132–33.

“自然主义者必须考虑”：条件反射讲义，第 82 页。

“The naturalist must consider”: Lectures on Conditioned Reflexes, p. 82.

受到电击后流口水，延迟三分钟后：同上，第 149、186-87 页。

drooling at an electric shock and after a three-minute delay: Ibid., pp. 149, 186–87.

每半小时流口水：条件反射，第 3 讲，第 41 页。

salivating on the half hour: Conditioned Reflexes, lecture 3, p. 41.

“我确信”：条件反射讲义，第 233 页。

“I am convinced”: Lectures on Conditioned Reflexes, p. 233.

区分顺时针和逆时针等：条件反射，第 7 讲，第 117-130 页，以及第 13 讲，第 222 页；条件反射讲义，第 140 页。

discriminating between clockwise and counterclockwise, etc.: Conditioned Reflexes, lecture 7, pp. 117–30, and lecture 13, p. 222; Lectures on Conditioned Reflexes, p. 140.

“路人的脚步声”：条件反射，第 2 讲，第 20 页。

“Footfalls of a passer-by”: Conditioned Reflexes, lecture 2, p. 20.

《寂静之塔》：条件反射讲义，第 144-146 页；弗洛洛夫，《巴甫洛夫和他的学派》，第 60-62 页；以及托德斯，《伊万·巴甫洛夫》，第 77-78 页。

“Tower of Silence”: Lectures on Conditioned Reflexes, pp. 144–46; Frolov, Pavlov and His School, pp. 60–62; and Todes, Ivan Pavlov, pp. 77–78.

“一艘准备战斗的潜艇”：巴甫洛夫和他的学校，第 61 页。

“a submarine ready for battle”: Pavlov and His School, p. 61.

巴甫洛夫在《条件反射讲义》第 141 页描述了上行和下行音阶实验。（音符为 D、E、升 F 和升 G。）

Pavlov describes the experiment on ascending and descending scales in Lectures on Conditioned Reflexes, p. 141. (The notes were D, E, F-sharp, and G-sharp.)

“植物的运动”：同上，第 59 页。

“The movement of plants”: Ibid., p. 59.

条件反射：托德斯等人认为，与更常见的“条件反射”相比，用“条件反射”来翻译巴甫洛夫的术语“ uslovnyi refleks ”更为恰当。参见《巴甫洛夫的生理工厂》，第244-246页。

conditional reflexes: Todes and others argue that this is a better translation of Pavlov’s term uslovnyi refleks than the more familiar “conditioned reflex.” See Pavlov’s Physiology Factory, pp. 244–46.

最终找到了副本：蒂姆·塔利在《巴甫洛夫的狗》（《当代生物学》 13，第 4 期：R118）中描述了他的搜索过程。

A copy was tracked down: Tim Tully described his search in “Pavlov’s Dogs” (Current Biology 13, no. 4: R118).

“巴甫洛夫的果蝇”：摘自冷泉港实验室 2003 年 2 月 17 日发布的新闻稿，可在实验室网站上查阅。

“Pavlov’s flies”: from a Cold Spring Harbor press release, February 17, 2003, available on the lab’s Web site.

“让狗成为人类的助手”：托德斯，《伊万·巴甫洛夫》，第 100 页。

“Let the dog, man’s helper”: Todes, Ivan Pavlov, p. 100.

10.罗伯特·米利肯：《在边境之地》

10. Robert Millikan: In the Borderland

古德斯坦，朱迪思·R. 《密立根的学校：加州理工学院的历史》。纽约：诺顿出版社，1991年。

Goodstein, Judith R. Millikan’s School: A History of the California Institute of Technology. New York: Norton, 1991.

霍尔顿，杰拉尔德·詹姆斯。《科学的想象力：案例研究》。纽约：剑桥大学出版社，1978年。

Holton, Gerald James. The Scientific Imagination: Case Studies. New York: Cambridge University Press, 1978.

米利肯，罗伯特·安德鲁斯。《自传》。伦敦：麦克唐纳出版社，1951年。

Millikan, Robert Andrews. Autobiography. London: Macdonald, 1951.

——。《电子：电子的分离、测量及其某些性质的测定》。芝加哥：芝加哥大学出版社，1924年。

———. The Electron: Its Isolation and Measurement and the Determination of Some of Its Properties. Chicago: University of Chicago Press, 1924.

——. 《科学与宗教中的进化》。纽黑文：耶鲁大学出版社，1927年。

———. Evolution in Science and Religion. New Haven: Yale University Press, 1927.

——. 《科学与生活》。波士顿：朝圣者出版社，1924年。

———. Science and Life. Boston: Pilgrim, 1924.

汤姆森，约瑟夫·约翰。《回忆录与反思》。纽约：麦克米伦出版社，1937年。

Thomson, Joseph John. Recollections and Reflections. New York: Macmillan, 1937.

温伯格，史蒂文。《亚原子粒子的发现》。纽约：弗里曼出版社，1990年。

Weinberg, Steven. The Discovery of Subatomic Particles. New York: Freeman, 1990.

题词：威廉·克鲁克斯，“论辐射物质 II”，《自然》 20（1879 年 9 月 4 日）：439–40。

epigraph: William Crookes, “On Radiant Matter II,” Nature 20 (September 4, 1879): 439–40.

米利肯误将这次谈话记为发生在圣诞前夜：他在《科学与宗教中的进化》第10-11页中描述了聆听伦琴讲座的情景。而实际的会面日期是1896年1月4日。（事实上，伦琴在1895年12月还在维尔茨堡发表过另一次演讲。）经常被引用的迈克尔逊讲座在《自传》第39-40页中有回顾。

Millikan misremembered the talk as occurring on Christmas Eve: He described listening to the Roentgen lecture in Evolution in Science and Religion, pp. 10–11. The actual date of the meeting was January 4, 1896. (Roentgen had, in fact, given another talk in December 1895 in Würzburg.) The oft-cited Michelson lecture is recalled in Autobiography, pp. 39–40.

赫兹论无线电波和光：“论电辐射”，《物理学年鉴》 36（1889）：769；载于《物理学资料汇编》，第549-61页。

Hertz on radio waves and light: “On Electric Radiation,” Annalen der Physik 36 (1889): 769; in A Source Book in Physics, pp. 549–61.

“我们还没有完全接近目标”：自传，第 11 页。

“We had not come quite as near”: Autobiography, p. 11.

Weinberg，《亚原子粒子的发现》，第 20-25 页、102-5 页，描述了放电管实验的历史。

The history of the discharge-tube experiments is described in Weinberg, The Discovery of Subatomic Particles, pp. 20–25, 102–5.

克鲁克斯的工作在《自然》杂志第20卷的两篇图文并茂的论文中有所描述：一篇是《论辐射物质》（1879年8月28日），页码为419-423；另一篇是《论辐射物质II》（1879年9月4日），页码为436-440。这两篇论文均被收录于戴维·M·奈特所著的《经典科学论文集：化学，第二辑。论化学元素的性质和排列》（纽约：美国爱思唯尔出版社，1970年），第89-98页。

Crookes’s work is described in two beautifully illustrated papers in volume 20 of Nature: “On Radiant Matter”(August 28, 1879): 419–23, and “On Radiant Matter II” (September 4, 1879): 436–40. Both are reprinted in David M. Knight, Classical Scientific Papers: Chemistry, Second Series. Papers on the Nature and Arrangement of the Chemical Elements (New York: American Elsevier, 1970), pp. 89–98.

“物质的第四种状态”：“辐射物质 II”，439。克鲁克斯借用了法拉第的术语。

“A fourth state of matter”: “Radiant Matter II,” 439. Crookes borrowed the term from Faraday.

伦琴的穿透射线：“论一种新型射线”，由亚瑟·斯坦顿翻译，《自然》 53（1896）：274-76。另一个译本摘录于《物理学资料汇编》（在我的第 3 章笔记中引用），第 600-10 页。

Roentgen’s penetrating rays: “On a New Kind of Rays,” translated by Arthur Stanton, Nature 53 (1896): 274–76. A different translation is excerpted in A Source Book in Physics (cited in my notes for chapter 3), pp. 600–10.

贝克勒尔的铀实验：“论磷光发射的射线”，Comptes Rendus 122 (1896): 420–21, 501–3；载于《物理学资料汇编》，第 610–13 页。

Becquerel’s uranium experiment: “On the Rays Emitted by Phosphorescence,” Comptes Rendus 122 (1896): 420–21, 501–3; in ASource Book in Physics, pp. 610–13.

J·J·汤姆逊在《哲学杂志》第44卷第293期（1897年）第293-316页发表了题为“阴极射线”的实验论文。斯蒂芬·赖特的《经典科学论文：物理学》（纽约：美国爱思唯尔出版社，1964年）中收录了该论文的影印本。温伯格在《亚原子粒子的发现》一书中第12-71页分析了该实验。

J. J. Thomson described his experiments in “Cathode Rays,” Philosophical Magazine 44, no. 293 (1897): 293–316. A facsimile appears in Stephen Wright, Classical Scientific Papers: Physics (New York: American Elsevier, 1964). Weinberg analyzes the experiment in Discovery of Subatomic Particles, pp. 12–71.

电子：这个名称最早由爱尔兰物理学家乔治·约翰斯通·斯托尼在《论电子或电原子》一文中使用，该文发表于《哲学杂志》 38 (1894)，第 418 页。

Electrons: The name had first been used by the Irish physicist George Johnstone Stoney in “Of the Electron or Atom of Electricity,” Philosophical Magazine 38 (1894), p. 418.

我的汤姆逊干涉仪是莱博尔德公司生产的，它还包括一个聚焦栅格，或者叫韦内尔特栅格（以发明它的德国物理学家韦内尔特的名字命名）。

My Thomson apparatus, made by Leybold, also included a focusing grid, or Wehnelt (named after the German physicist who invented it).

每克物质带电量为2.5 × 10⁸^库仑：荷质比的公式为v/Br，其中v为电子速度，B为磁场强度，r为弯曲电子束的半径。这相当于

2.5 × 10⁸ coulombs of charge per gram: The formula for the charge-to-mass ratio is v/Br where v is the velocity of the electrons, B is the strength of the magnetic field, and r is the radius of the curving beam. This turns out to be equivalent to

a = 线圈半径

a = the radius of the coils

N = 线圈中导线的匝数

N = the number of turns of wire in the coils

V = 阳极上的加速电压

V = the accelerating voltage on the anode

I = 线圈中的电流（安培）

I = the amperes of current in the coils

r = 梁的半径

r = the radius of beam

µ ₀是一个称为磁导率常数的数字，它是一个转换因子，使所有单位（伏特、安培、库仑、厘米和克）都能很好地相互配合。

µ₀ is a number called the permeability constant , a conversion factor that makes all the units—volts, amperes, coulombs, centimeters, and grams—play well together.

假设电源电压为 100 伏，则每秒流过 100 瓦灯泡的电量是多少？

the quantity of electricity flowing each second through a 100-watt bulb: assuming, of course, a power source of 100 volts.

电子的数值大约是原子核的1000倍：汤姆逊还考虑过电子的质量可能更大、电荷可能更小的可能性，但这与菲利普·莱纳德的实验结果相矛盾，莱纳德的实验表明阴极射线粒子比空气分子轻得多。

The value for the electron was about a thousand times greater: Thomson also considered the possibility that electrons might have a larger mass and a smaller charge, but that would have contradicted experiments by Philip Lenard suggesting that cathode-ray corpuscles were considerably lighter than molecules of air.

感觉自己像个过气人物：米利肯在自传第 84-85 页讲述了这个故事。

feeling like a has-been: Millikan tells the story in Autobiography, pp. 84–85.

卡文迪什利用蒸汽云进行的实验由H.A.威尔逊完成，标志着对汤姆逊和J.S.E.汤森早期尝试的改进。这些实验总结于《自传》（第85-87页）和《电子》（第45-57页）。温伯格在《亚原子粒子的发现》（第91-95页）中分析了这项工作。实验中使用的装置——威尔逊云室——由苏格兰人C.T.R.威尔逊发明，他曾用它观测宇宙射线的轨迹。

The Cavendish experiment with the vapor cloud was done by H. A. Wilson and marked an improvement over earlier attempts by Thomson and J. S. E. Townsend. The experiments are summarized in Autobiography, pp. 85–87, and in The Electron, pp. 45–57. Weinberg analyzes the work in Discovery of Subatomic Particles, pp. 91–95. The device used in the experiments, a Wilson cloud chamber, was invented by the Scotsman C. T. R. Wilson, who used it to observe the tracks of cosmic rays.

“就像穆罕默德的棺材一样”：自传，第 89 页。奇怪的是，汤姆森十四年前在自己的回忆录《回忆与反思》第 343 页中也使用了同样的比喻。

“like Mohammed’s coffin”: Autobiography, p. 89. Curiously, Thomson used the same analogy fourteen years earlier in his own memoirs, Recollections and Reflections, p. 343.

米利肯的水滴实验：自传，第 89-91 页。有关分析，请参阅霍尔顿《科学的想象力》中的“亚电子、预设和米利肯-埃伦哈夫特之争”，第 42-46 页。

Millikan’s water-drop experiments: Autobiography, pp. 89–91. For an analysis see “Subelectrons, Presuppositions and the Millikan-Ehrenhaft Dispute,” in Holton, The Scientific Imagination, pp. 42–46.

“1、2、3、4 或其他一些精确的倍数”：自传，第 90 页。密立根报告他的结果为 4.65 × 10 ^-10静电单位（也称为静库仑），换算成库仑为 1.55 × 10 ^-19库仑。

“1, 2, 3, 4, or some other exact multiple”: Autobiography, p. 90. Millikan reported his result as 4.65 × 10^-10 electrostatic units (also called statcoulombs), which converts to 1.55 × 10^-19 coulombs.

温尼伯会议的描述见《科学的想象力》第 48-50 页。米利肯对回家火车之旅的回忆见《自传》第 91-92 页。

The Winnipeg meeting is described in The Scientific Imagination, pp. 48–50. Millikan’s recollection about the train trip home is in Autobiography, pp. 91–92.

“这尚未成为可能”：科学的想象力，第 50 页。

“it has not yet been possible”: The Scientific Imagination, p. 50.

“我看到了最美丽的景象”：哈维·弗莱彻，“我与密立根一起进行油滴实验”，《今日物理》（1982 年 6 月）：45。

“I saw a most beautiful sight”: Harvey Fletcher, “My Work with Millikan on the Oil-Drop Experiment,” Physics Today (June 1982): 45.

斯托克斯定律（以十九世纪科学家乔治·G·斯托克斯爵士的名字命名）描述了微小球形物体在水或空气等粘性介质中的下落规律。密立根后来调整了该方程，使其更适用于像油滴这样微小的物体。

Stokes’s law (named after the nineteenth-century scientist Sir George G. Stokes) describes how small spherical objects fall in a viscous medium like water or air. Millikan later adjusted the equation so that it applied more closely to objects as tiny as his oil drops.

“亚电子”：这位物理学家是维也纳大学的费利克斯·埃伦哈夫特。

“subelectrons”: The physicist was Felix Ehrenhaft of the University of Vienna.

“我绝对不会相信”：弗莱彻在《我与米利肯的合作》第 46 页讲述了这个故事。

“I never would have believed it”: Fletcher told the story in “My Work with Millikan,” p. 46.

米利肯和弗莱彻将结果写成文章：“离子的分离、其电荷的精确测量以及斯托克斯定律的修正”，《科学》 30（1910 年 9 月）：436-448。

Millikan and Fletcher wrote up the results: “The Isolation of an Ion, a Precision Measurement of Its Charge, and the Correction of Stokes’s Law,” Science 30 (September 1910): 436–48.

“非常低，肯定出了什么问题”：《科学的想象力》，第 70-71 页，以及“为罗伯特·安德鲁斯·密立根辩护”，《工程与科学》 63，第 4 期（2000 年）：34-35。

“Very low something wrong”: The Scientific Imagination, pp. 70–71, and “In Defense of Robert Andrews Millikan,” Engineering and Science 63, no. 4 (2000): 34–35.

“见过那个实验的人”：自传，第 96-98 页。

“He who has seen that experiment”: Autobiography, pp. 96–98.

1.5924 × 10 ^-19库仑：或 4.774 × 10 ^-10统计库仑。

1.5924 × 10^-19 coulombs: or 4.774 × 10^-10 statcoulombs.

弗莱彻在《我与米利肯共事》一书中讲述了他的故事。

Fletcher told his story in “My Work with Millikan.”

米利肯居高临下的态度：例如，参见《自传》第 70 页。大卫·古德斯坦在《为罗伯特·米利肯辩护》中给出了其他例子。

Millikan’s patronizing manner: See, for example, Autobiography, p. 70. David Goodstein gives other examples in “In Defense of Robert Millikan.”

霍尔顿和古德斯坦的文章描述了围绕密立根数据的争议。

The controversy over Millikan’s data is described in the essays by Holton and Goodstein.

致谢

ACKNOWLEDGMENTS

如果没有身边这么多优秀的图书馆，我真不知道这本书该如何写出来。首先要介绍的是美丽的米姆图书馆，它就在圣约翰学院山坡上，由西南建筑师约翰·高·米姆设计，馆藏丰富，涵盖了从托勒密的《天文学大成》到密立根的《电子论》等众多科学史经典著作。我甚至还找到了阿尔伯特·迈克尔逊1878年测量光速时的手写笔记的影印版。同样令人惊喜的还有位于市中心的圣达菲公共图书馆——它的阅览室本身就是一件建筑瑰宝——那里的参考咨询馆员帮我办理了好几笔馆际互借。我离圣达菲最远的地方是位于阿尔伯克基的新墨西哥大学，那里的旧版装订期刊仍然摆放在开放式书架上，而不是被封存在缩微胶片的牢笼里。

I DON’T know how this book could have been written without so many good libraries around me. First is the beautiful Meem Library, just up the hill at St. John’s College, designed by the southwestern architect John Gaw Meem and filled with classics in the history of science from Ptolemy’s Almagest to Millikan’s The Electron. I was actually able to find a facsimile edition of Albert Michelson’s handwritten notes from his 1878 measurement of the speed of light. Just as special is the Santa Fe Public Library downtown—its reading room is another architectural treasure—where the reference librarians helped me secure several interlibrary loans. The farthest I had to stray from Santa Fe was to the University of New Mexico in Albuquerque, where the old bound journals are still on the open shelves and not relegated to the prison of microfilm.

早期，圣约翰大学校长约翰·巴尔科姆的热情给了我极大的鼓舞。我还要感谢该校前实验室主任汉斯·冯·布里森，是他让我第一次接触到汤姆逊和密立根的实验；以及威廉·多纳休、彼得·佩西奇和内德·沃尔平三位教授，他们对我的手稿提出了许多富有洞见的意见。我感谢哈佛大学的欧文·金格里奇和杰拉尔德·霍尔顿，以及伯克利大学的约翰·海尔布伦给予我的指导。约翰·霍普金斯大学的丹尼尔·托德斯对巴甫洛夫的研究提出了许多有益的见解，康奈尔大学的罗尔德·霍夫曼对拉瓦锡的研究也同样如此。

Early on, the enthusiasm of St. John’s president, John Balkcom, was an inspiration. I also thank Hans von Briesen, the school’s former laboratory director, who gave me my first experience with the Thomson and Millikan experiments, and William Donahue, Peter Pesic, and Ned Walpin, faculty members who made insightful comments on the manuscript. I’m grateful to Owen Gingerich and Gerald Holton at Harvard and John Heilbron at Berkeley for their advice. Daniel Todes at Johns Hopkins made many helpful observations about Pavlov, as did Roald Hoffmann at Cornell about Lavoisier.

一如既往，感谢我的朋友们自愿担任早期读者：帕特里克·科菲、路易莎·吉尔德、邦妮·李·拉·玛德琳、大卫·帕德瓦和厄休拉·帕夫利什。科马克·麦卡锡的细致阅读促使我删去了分号和一些使用不当的逗号（其中一些后来又偷偷加了回去）。在最后阶段，玛拉·瓦茨敏锐的审视、渊博的学识和良好的判断力，以及艾莉森·肯特精湛的艺术造诣，都极大地提升了本书的质量。

As always, thanks go to my friends who volunteered to be early readers: Patrick Coffey, Louisa Gilder, Bonnie Lee La Madeleine, David Padwa, and Ursula Pavlish. A microscopic read by Cormac McCarthy compelled me to expunge semicolons and underworked commas (a few of which have snuck back in). In the final stage, the book was greatly improved by the sharp scrutiny, erudition, and good sense of Mara Vatz and the artistry of Alison Kent.

这已经是我与克诺夫出版社的乔恩·西格尔合作的第六本书了，也是与乔纳森·凯普出版社和博德利出版社的威尔·苏尔金合作的第三本书。他们的建议和鼓励弥足珍贵，我的经纪人埃丝特·纽伯格也功不可没，她从一开始就陪伴着我。在克诺夫出版社，我还要感谢编辑助理凯尔·麦卡锡、设计师弗吉尼亚·谭、文案主管莉迪亚·布赫勒和制作编辑凯瑟琳·弗里德拉，感谢他们精湛的技艺和耐心，将手稿最终变成了一本书。

This is the sixth book I’ve had the good fortune to do with Jon Segal at Knopf and the third with Will Sulkin at Jonathan Cape and Bodley Head. Their counsel and encouragement are invaluable, as are those of my agent, Esther Newberg, who has been there from the start. At Knopf I would also like to thank editorial assistant Kyle McCarthy, designer Virginia Tan, copy chief Lydia Buechler, and production editor Kathleen Fridella for their skill and patience in turning a manuscript into a book.

插图作者名单

ILLUSTRATION CREDITS

第一章伽利略·伽利莱，作者：奥塔维奥·莱奥尼。图片来自维基共享资源。

Chapter 1 Galileo Galilei, by Ottavio Leoni. Wikimedia Commons.

第一章十九世纪早期斜面实验的演示。插图由艾莉森·肯特绘制。

Chapter 1 An early nineteenth-century demonstration of the inclined plane experiment. Drawing by Alison Kent.

Chapter 1 A page from Galileo’s notebook. Folio 107v, vol. 72. Reproduced by kind permission of the Ministero per i Beni e le Attività Culturali, Italy/Biblioteca Nazionale Centrale. Firenze. This image cannot be reproduced in any form without the authorization of the Library, the owners of the copyright.

第一章伽利略的手指。经科学史研究所和博物馆许可使用。

Chapter 1 Galileo’s finger. By permission of Istituto e Museo di Storia della Scienza.

第二章威廉·哈维，作者：威廉·范·贝梅尔。根据雅各布·霍布拉肯的木刻版画绘制。出自《罗斯威尔·帕克：医学史概要》（费城：FA·戴维斯公司，1897年），第156页。

Chapter 2 William Harvey, by Willem van Bemmel. From a wood engraving by Jacob Houbraken of a painting. In Roswell Park, An Epitome of the History of Medicine (Philadelphia: The F. A. Davis Company, 1897), p. 156.

第二章法布里库斯解剖剧场。出自雅各布·菲利波·托马西尼的《帕塔维努姆体育馆》（乌迪内：尼古拉斯·希拉特，1654年）中的一幅十七世纪版画。公共领域。

Chapter 2 The Anatomy Theater of Fabricus. From a seventeenth-century engraving in Jacopo Filippo Tomasini, Gymnasium Patavinum (Udine: Nicolas Schiratt, 1654). Public domain.

第 2 章格雷氏解剖学中的人体心脏横截面图。亨利·格雷，《人体解剖学》，第 20 版（费城：Lea & Febiger，1918 年）。

Chapter 2 Cross section of a human heart from Gray’s Anatomy. Henry Gray, Anatomy of the Human Body, 20th edition (Philadelphia: Lea & Febiger, 1918).

第二章血管，摘自哈维的《心脏运动》，1628 年。

Chapter 2 Blood vessels, from Harvey’s Motion of the Heart, 1628.

第三章艾萨克·牛顿，戈弗雷·内勒爵士著，1689 年。

Chapter 3 Isaac Newton, by Sir Godfrey Kneller, 1689.

第三章乔瓦尼·巴蒂斯塔·皮托尼所作的 《艾萨克·牛顿爵士寓言纪念碑》。经英国剑桥菲茨威廉博物馆许可使用。2005年我去参观这幅画时，它已被移至三一学院图书馆的楼梯间。

Chapter 3 An Allegorical Monument to Sir Isaac Newton, by Giovanni Battista Pittoni. By permission of the Fitzwilliam Museum, Cambridge, England. In 2005, when I went to see the painting, it had been moved to a stairway at the Trinity College Library.

第三章在显微镜下观察，“一小块白色的毛状霉菌”。出自罗伯特·胡克，《显微图谱》，1665年。图十二，第124页和125页之间。

Chapter 3 Viewed under a microscope, “a small white spot of hairy mould.” From Robert Hooke, Micrographia, 1665. Schem: XII, between pp. 124 and 125.

第三章用于展示牛顿环的透镜夹层结构。根据哈佛大学自然科学讲座中的图示重新绘制。图片来自维基共享资源。

Chapter 3 A lens sandwich used to show Newton’s rings. Redrawn from a diagram in the Harvard Natural Sciences Lectures. Wikimedia Commons.

第三章牛顿用自己的眼睛做实验。摘自他的笔记本。手稿编号 ADD 3975，第 15 页。经剑桥大学图书馆理事会许可。

Chapter 3 Newton’s experiment with his own eye. A page from his notebooks. MS ADD 3975, p. 15. By permission of the Syndics of Cambridge University Library.

第三章牛顿绘制的《十字架实验》。出自《牛顿书信集》第一卷，第107页。（MS 361卷，第二卷，第45页。）经牛津大学新学院院长和院士许可。

Chapter 3 Newton’s drawing of his Experimentum Crucis. From Newton’s Correspondence I, p. 107. (MS 361 vol. 2. fol, 45.) By permission of the Warden and Fellows, New College, Oxford.

第四章安托万·洛朗·拉瓦锡。维基共享资源。

Chapter 4 Antoine-Laurent Lavoisier. Wikimedia Commons.

第四章钻石焚烧。布里奇曼艺术图书馆。

Chapter 4 Incinerating diamonds. Bridgeman Art Library.

第四章鹈鹕烧瓶。约翰·弗伦奇，《蒸馏的艺术》（伦敦，1651 年）。

Chapter 4 A pelican flask. John French, The Art of Distillation (London, 1651).

第 4 章玛丽·安妮·皮埃尔特·保尔兹。阿伦茨根据一位不知名艺术家的蜡笔肖像雕刻而成。摘自 Édouard Grimaux, Lavoisier, 1743–1794, D'après Sa Correspondance, Ses Manuscrits, Ses Papiers De Famille Et D'autres Documents Inédits，第 3 版（巴黎：F. Alcan，1899）。

Chapter 4 Marie Anne Pierrette Paulze. An engraving by Arents from a pastel portrait by an unknown artist. From Édouard Grimaux, Lavoisier, 1743–1794, D’après Sa Correspondance, Ses Manuscrits, Ses Papiers De Famille Et D’autres Documents Inédits, 3. éd (Paris: F. Alcan, 1899).

第四章用放大镜在罐中燃烧铅丹。出自拉瓦锡，《化学回忆录》（巴黎，1805 年）。

Chapter 4 Burning litharge in a jar with a magnifying glass. From Lavoisier, Mémoires De Chimie (Paris, 1805).

第四章在“火烈鸟烧瓶”中加热汞。拉瓦锡，《化学原理》（巴黎，1784 年）。图版 4，图 2。

Chapter 4 Heating mercury in a “flamingo flask.” Lavoisier, Elements of Chemistry (Paris, 1784). Plate 4, figure 2.

第五章路易吉·伽伐尼。维基共享资源。

Chapter 5 Luigi Galvani. Wikimedia Commons.

第五章西默的袜子。出自让-安托万·诺莱，《论电的信》第三卷（1767 年）。

Chapter 5 Symmer’s socks. In Jean-Antoine Nollet, Lettres sur l’électricité III (1767).

第五章十八世纪的静电机器。摘自让-安托万·诺莱 (Jean-Antoine Nollet) 的《军团电力论文集》 (1750)。

Chapter 5 An eighteenth-century static electricity machine. From Jean-Antoine Nollet, Essai sur l’électricité des corps (1750).

第五章本杰明·富兰克林绘制的两个莱顿瓶。本杰明·富兰克林，《电学实验与观察》（伦敦：E. Cave，圣约翰门，1751 年）。

Chapter 5 Benjamin Franklin’s drawing of two Leyden jars. Benjamin Franklin, Experiments and Observations on Electricity (London: E. Cave, at St. John’s Gate, 1751).

第五章闪电引起的肌肉收缩。来自 Luigi Galvani，De Viribus Electricitatis in Motu Musulari Commentarius，1791。表 II。

Chapter 5 Muscular contractions caused by lightning. From Luigi Galvani, De Viribus Electricitatis in Motu Musculari Commentarius, 1791. Table II.

第五章静电和青蛙腿。来自路易吉·加尔瓦尼 (Luigi Galvani) 的《肌肉运动评论》中的《De Viribus Electricitatis》。表一.

Chapter 5 Static electricity and frogs’ legs. From Luigi Galvani, De Viribus Electricitatis in Motu Musculari Commentarius. Table I.

第五章伽伐尼无外导体实验。来自 Marc Sirol，Galvani Et Le Galvanisme。 L'électricité Animale（巴黎：Vigot frères，1939）。

Chapter 5 Galvani’s experiment without external conductors. From Marc Sirol, Galvani Et Le Galvanisme. L’électricité Animale (Paris: Vigot frères, 1939).

第五章伏特的电堆。摘自亚历山德罗·伏特，《论不同种类导电物质仅接触所产生的电》。载于亚历山大·伏特致约瑟夫·班克斯爵士的信（1800年）。

Chapter 5 Volta’s electrical pile. From Alessandro Volta, On the Electricity Excited By the Mere Contact of Conducting Substances of Different Kinds. In a Letter From Alexander Volta to Sir Joseph Banks, Bart (1800).

第六章迈克尔·法拉第。古腾堡计划档案馆。

Chapter 6 Michael Faraday. Project Gutenberg Archives.

第六章艾达·洛芙莱斯夫人。创作于1838年。图片来自维基共享资源。

Chapter 6 Lady Ada Lovelace. Dated 1838. Wikimedia Commons.

第六章奥斯特的实验。摘自法拉第《物质的力》（1868年），第85页。

Chapter 6 Oersted’s experiment. From Faraday’s Forces of Matter (1868), p. 85.

第六章摘自法拉第的日记，一根导线绕着磁铁旋转。1821年9月3日，第50页。

Chapter 6 From Faraday’s diary, a wire rotating around a magnet. Sept. 3, 1821, p. 50.

第六章法拉第的感应环图。摘自他的日记。1831年8月29日，第367页。

Chapter 6 Faraday’s drawings of an induction ring. From his diary. Aug. 29, 1831, p. 367.

第六章反射偏振和通过偏振晶体的偏振。根据1955年7月《科学美国人》杂志上的图表重新绘制。

Chapter 6 Polarization by reflection and through a polarizing crystal. Redrawn based on a diagram in Scientific American, July 1955.

第六章极化实验。摘自法拉第日记，第四卷，第264页。

Chapter 6 The polarization experiment. From Faraday’s Diary, vol. 4, p. 264.

第 7 章James Prescott Joule。维基共享资源。出自 Robert Andrews Millikan 和 Henry Gordon Gale 的《实用物理学》，1920 年（首次出版于 1913 年）。

Chapter 7 James Prescott Joule. Wikimedia Commons. From Robert Andrews Millikan and Henry Gordon Gale, Practical Physics, 1920 (first published 1913).

第七章詹姆斯·瓦特于十八世纪末制造的蒸汽机。摘自罗伯特·H·瑟斯顿于1920年出版的《蒸汽机发展史》（原版出版于1878年）。

Chapter 7 A late-eighteenth-century steam engine made by James Watt. From A History of the Growth of the Steam-Engine by Robert H. Thurston, 1920 (originally published 1878).

第七章水车。密立根和盖尔。

Chapter 7 A water wheel. Millikan and Gale.

第七章焦耳的电动机。摘自他的《科学论文集》第一卷，第17页。

Chapter 7 Joule’s electric motor. From his Scientific Papers, vol. 1, p. 17.

第 7 章焦耳发生器。焦耳，《科学论文集》，第 1 卷，第 125 页。

Chapter 7 Joule’s generator. Joule, Scientific Papers, vol. 1, p. 125.

第七章用于转动发电机曲柄的重物和滑轮。摘自焦耳，《科学论文集》，第一卷，第150页。

Chapter 7 Weights and pulleys to turn the generator crank. From Joule, Scientific Papers, vol. 1 p. 150.

第七章焦耳实验的改进版本。《科学论文集》，第一卷，“热的机械当量”图版二。见第298页之后。

Chapter 7 The refined version of Joule’s experiment. Scientific Papers, vol. 1. Plate II of “Mechanical Equivalent of Heat.” Appears after p. 298.

第八章阿尔伯特·A·米歇尔森。

Chapter 8 Albert A. Michelson.

第 8 章罗默绘制的从地球绕太阳轨道不同位置观测到的木星 (B) 遮蔽其卫星木卫一 (DC) 的示意图。出自他的论文《关于光运动的论证》(1878 年)。

Chapter 8 A diagram by Roemer of Jupiter (B) eclipsing its moon Io (DC) as viewed from different points in earth’s orbit around the sun. From his paper, “A Demonstration Concerning the Motion of Light” (1878).

第八章菲佐实验。摘自恩斯特·马赫，《物理光学原理》，英文译本，1926年，第25页。

Chapter 8 The Fizeau experiment. From Ernst Mach, The Principles of Physical Optics, English translation, 1926, p. 25

第八章傅科实验。摘自迈克尔逊，《美国海军学院光速实验测定》，安纳波利斯，1878 年。

Chapter 8 The Foucault experiment. From Michelson, “Experimental Determination of the Velocity of Light Made at the U.S. Naval Academy,” Annapolis, 1878.

第八章迈克尔逊旋转镜。“光速的实验测定”。

Chapter 8 Michelson’s rotating mirror. “Experimental Determination of the Velocity of Light.”

第 8 章托马斯·杨的干涉图样。摘自其《自然哲学与机械艺术讲义》第39 讲（1807 年）。

Chapter 8 Thomas Young’s interference pattern. From Lecture XXXIX of his Course of Lectures on Natural Philosophy and the Mechanical Arts (1807).

第 8 章迈克尔逊的第一台干涉仪，从顶部和侧面观察。出自《地球与发光以太的相对运动》（1887 年）。

Chapter 8 Michelson’s first interferometer, viewed from the top and from the side. From “The Relative Motion of the Earth and the Luminiferous Aether” (1887).

第 8 章迈克尔逊-莫雷实验。摘自《论地球和发光以太的相对运动》（1887 年）。

Chapter 8 The Michelson-Morley experiment. From “On the Relative Motion of the Earth and the Luminferous Aether” (1887).

第九章伊万·巴甫洛夫。图片由圣彼得堡实验医学研究所提供。

Chapter 9 Ivan Pavlov. Courtesy the Institute of Experimental Medicine, St. Petersburg.

第 9 章实验医学研究所的场景。摘自Niva 7 (1891): 156–57。

Chapter 9 Scenes from the Institute of Experimental Medicine. From Niva 7 (1891): 156–57.

第九章婴儿对火产生回避反射。威廉·詹姆斯，《心理学原理》（1890），第25页。

Chapter 9 A baby acquiring an avoidance reflex to fire. William James, The Principles of Psychology (1890), p. 25.

第九章训练狗在两个机械刺激器刺破其皮肤时分泌唾液。引自巴甫洛夫《动物高级神经活动的生理学和心理学》（1916）。《条件反射讲义》，第27页。

Chapter 9 Training a dog to salivate when two mechanical stimulators prick its skin. From Pavlov, “Physiology and Psychology in the Study of the Higher Nervous Activity of Animals” (1916). In Lectures on Conditioned Reflexes, p. 27.

第九章升调

Chapter 9 Ascending scale

第九章降序音阶。

Chapter 9 Descending scale.

第 9 章巴甫洛夫的狗。摘自 Tim Tully，“巴甫洛夫的狗”，《当代生物学》 13，第 4 期：R118。

Chapter 9 Pavlov’s dogs. From Tim Tully, “Pavlov’s Dogs,” Current Biology 13, no. 4: R118.

第九章 纪念一只狗的纪念碑。图片由实验医学研究所提供。

Chapter 9 Monument to a Dog. Courtesy the Institute of Experimental Medicine.

第 10 章罗伯特·密立根。摘自罗伯特·安德鲁斯·密立根，《科学与生活》（纽约州弗里波特：图书馆出版社，1969 年）。

Chapter 10 Robert Millikan. From Robert Andrews Millikan, Science and Life (Freeport, N.Y: Books for Libraries Press, 1969).

第十章伦琴射线照射手掌内部。图片来自 P. Spies，《麦克卢尔杂志》，1896 年 4 月，第 404 页。

Chapter 10 Roentgen rays look inside a hand. From a photograph by P. Spies, McClure’s Magazine, April 1896, p. 404.

第十章克鲁克斯管。摘自《论辐射物质》（1879）。

Chapter 10 Crookes tubes. From “On Radiant Matter” (1879).

第十章JJ·汤姆逊实验。摘自《阴极射线》（1897）。

Chapter 10 J. J. Thomson experiment. From “Cathode Rays” (1897).

第十章汤姆逊装置的现代版本。插图由艾莉森·肯特绘制。

Chapter 10 A modern version of the Thomson apparatus. Drawing by Alison Kent.

第 10 章威尔逊云室。摘自 CTR Wilson，“关于一种用于使气体中电离粒子的径迹可见的膨胀装置及其使用所获得的一些结果”，伦敦皇家学会会刊（A 系列）87 (1912)，第 595 号：277–92。

Chapter 10 Wilson cloud chamber. From C. T. R. Wilson, “On an Expansion Apparatus for making Visible the Tracks of Ionising Particles in Gases and some Results obtained by its Use,” Proceedings of the Royal Society of London (Series A) 87 (1912), no. 595: 277–92.

第 10 章密立根油滴实验的早期版本。摘自罗伯特·密立根，“离子的分离、对其电荷的精确测量以及斯托克斯定律的修正”，《物理评论》（第一辑）32 (1911)。

Chapter 10 Early version of the Millikan oil-drop experiment. From Robert Millikan, “The Isolation of an Ion, a Precision Measurement of its Charge, and the Correction of Stokes’s Law,” Physical Review (Series I) 32 (1911).

第 10 章后来的版本。摘自密立根的论文“关于基本电荷和阿伏伽德罗常数”，《物理评论》（第一辑）32（1911）。

Chapter 10 A later version. From Millikan’s paper “On the Elementary Electrical Charge and the Avogadro Constant,” Physical Review (Series I) 32 (1911).

第十章菲利普·哈里斯公司密立根仪器。艾莉森·肯特绘图。

Chapter 10 Philip Harris Co. Millikan apparatus. Drawing by Alison Kent.

关于作者的说明

A NOTE ABOUT THE AUTHOR

乔治·约翰逊为《纽约时报》、《科学美国人》、《连线》、《Slate》等刊物撰写科学文章。他最近的著作包括《莱维特小姐的星辰：发现如何测量宇宙的女性不为人知的故事》和《穿越时间的捷径：通往量子计算机之路》。其他著作包括《奇异之美：默里·盖尔曼与二十世纪物理学的革命》和《心灵之火：科学、信仰与秩序的探索》，这两部作品均入围英国皇家学会图书奖。他曾荣获美国科学促进会科学新闻奖，是圣达菲科学写作工作坊的联合主任，也是前艾丽西亚·帕特森研究员。他现居圣达菲，个人网站为www.talaya.net。

GEORGE JOHNSON writes about science for The New York Times, Scientific American, Wired, Slate, and other publications. His most recent books are Miss Leavitt’s Stars: The Untold Story of the Woman Who Discovered How to Measure the Universe and A Shortcut Through Time: The Path to the Quantum Computer. Others include Strange Beauty: Murray Gell-Mann and the Revolution in Twentieth-Century Physics and Fire in the Mind: Science, Faith, and the Search for Order, which were finalists for the Royal Society Book Prize. A winner of the AAAS Science Journalism Award, he is codirector of the Santa Fe Science Writing Workshop and a former Alicia Patterson fellow. He lives in Santa Fe and can be found on the Web at www.talaya.net.

乔治·约翰逊的其他作品

ALSO BY GEORGE JOHNSON

莱维特小姐的星空：发现如何测量宇宙的女性不为人知的故事

Miss Leavitt’s Stars: The Untold Story of the Woman Who Discovered How to Measure the Universe

穿越时间的捷径：通往量子计算机之路

A Shortcut Through Time: The Path to the Quantum Computer

奇异之美：默里·盖尔曼与二十世纪物理学的革命

Strange Beauty: Murray Gell-Mann and the Revolution in Twentieth-Century Physics

心灵之火：科学、信仰与秩序的探寻

Fire in the Mind: Science, Faith, and the Search for Order

在记忆的宫殿里：我们如何在头脑中构建世界

In the Palaces of Memory: How We Build the Worlds Inside Our Heads

心灵机器：人工智能新科学内幕

Machinery of the Mind: Inside the New Science of Artificial Intelligence

恐惧的缔造者：美国政治中的阴谋论与偏执

Architects of Fear: Conspiracy Theories and Paranoia in American Politics

这是一本由阿尔弗雷德·A·克诺夫出版的博佐伊犬书籍。

THIS IS A BORZOI BOOK PUBLISHED BY ALFRED A. KNOPF

www.aaknopf.com

Knopf、Borzoi Books 和版权页均为 Random House, Inc. 的注册商标。

Knopf, Borzoi Books, and the colophon are registered trademarks of Random House, Inc.

美国国会图书馆出版物编目数据

Library of Congress Cataloging-in-Publication Data

约翰逊，乔治，[日期]

Johnson, George, [date]

乔治·约翰逊著《十大最美实验》——第一版

The ten most beautiful experiments / by George Johnson.—1st ed.

厘米

p. cm.

包含参考文献。

Includes bibliographical references.

1. 科学——实验。I. 标题。

1. Science—Experiments. I. Title.

Q 182.3.j65 2008

Q182.3.j65 2008

507.8—dc22 2007027839

电子书ISBN：978-0-307-26866-2

eISBN: 978-0-307-26866-2

v3.0